Answer:
D) Water splashing
Explanation:
Displacement is about moving something from its original place. In A, B, and C nothing is being moved. This makes D the only answer!
How many joules of heat are given off when 5.00g of water cool from 348.0K to 298.0K?
Answer:
Q = -1045 J
Explanation:
Given data:
Mass of water = 5.00 g
Initial temperature = 348.0 K
Final temperature = 298.0 K
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.K
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 298.0 K - 348.0 K
ΔT = - 50 K
Q = 5.0 g ×4.18 J/g.K× - 50 K
Q = -1045 J
What would humans need to live on another planet?
Answer:
In its astrobiology roadmap, NASA has defined the principal habitability criteria as "extended regions of liquid water, conditions favorable for the assembly of complex organic molecules, and energy sources to sustain metabolism". In August 2018, researchers reported that water worlds could support life.
how will we know that a chemical reaction happened if we cant see atoms??
we can do soo by noticing any colour change, or by the formation of an insoluble precipitate or by the evolution of a gas.
The half-life for a first-order reaction is 32 s. What was the original concentration if, after 2.0 minutes, the reactant concentration is 0.062 M?
Answer:
0.834 M.
Explanation:
Hello!
In this case, since this is a first-order reaction, we can infer that the half-life and the rate constant are related via:
[tex]t_{1/2}=\frac{ln(2)}{k}[/tex]
Thus, we are able to compute the rate constant:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{32s}\\\\k=0.0217s^{-1}[/tex]
Next, since we have the resulting concentration of the reactant and we need the initial one, we proceed as shown below with the rate law:
[tex]A=A_0exp(-kt)\\\\A_0=\frac{A}{exp(-kt)} \\\\A_0=\frac{0.062M}{exp(-0.0217s^{-1}*2.0min*\frac{60s}{1min} )}\\\\A_0=0.834M[/tex]
Best regards!
What mass of carbon monoxide gas (CO) would occupy a volume of 4.30 L at STP? Explain how you got the answer.
Answer:
5.38 g of CO.
Explanation:
From the question given above, the following data were obtained:
Volume of CO = 4.3 L
Mass of CO =?
Next, we shall determine the number of mole of CO that occupied 4.3 L at STP. This can be obtained as follow:
Recall = 1 mole of any gas occupy 22.4 L at STP.
1 mole of CO occupied 22.4 L at STP.
Therefore, Xmol of CO will occupy 4.3 L at STP i.e
Xmol of CO = 4.3 / 22.4
Xmol of CO = 0.192 mole.
Thus, 0.192 mole of CO occupy 4.3 L at STP.
Finally, we shall determine the mass of CO as follow:
Mole of CO = 0.192 mole.
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO =?
Mole = mass /Molar mass
0.192 = mass of CO / 28
Cross multiply
Mass of CO = 0.192 × 28
Mass of CO = 5.38 g.
Therefore, 5.38 g of CO occupied 4.3 L at STP.
What is the reducing agent in the following reaction
5Fe2+(aq) + MnO4-(aq) + 8H+(aq) → 5Fe3+(aq) + Mn2+(aq) + 4H2O(I)
A. MnO4-
B. Fe3+
C. Mn2+
D. Fe2+
E. H+
Answer: [tex]Fe^{2+}[/tex] is the reducing agent
Explanation:
Oxidation reaction : When there is an increase in oxidation state number.
Reduction reaction : when there is a decrease in oxidation state number.
[tex]5Fe^{2+}(aq)+MnO_4^-(aq)+8H^+(aq)\rightarrow 5Fe^{3+}(aq)+Mn^{2+}(aq) +4H_2O(l)[/tex]
Fe has undergone oxidation, as its oxidation state is changing from+2 to +3.
Mn has undergone reduction, as its oxidation state is changing from +7 to +2.
The chemical agent which itself get oxidized and reduce others is called reducing agent. [tex]Fe^{2+}[/tex] is a reducing agent.
The chemical agent which itself get reduced and oxidize others is called oxidizing agent. [tex]MnO_4^-[/tex] is an oxidizing agent.
.
To be considered a source of water pollution, the source must include a chemical.
Please select the best answer from the choices provided
ОТ
OF
Answer:
it is true because i just took the test and i did research on it
Explanation:
i study this and because i did research
Answer:
trueeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Explanation: eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Write a complete chemical formula, including physical state symbol, for each element listed below in its standard state.The first row of the table has been completed.Element FormulaIron Fe(s)Phosphorus Neon Chlorine
Answer:
Phosphorus P (s)
Neon Ne (g)
Chlorine Cl (g)
Explanation:
Iron: Fe(s) - The (s) denotes that iron is in its solid state.
Phosphorus: P(s) - The (s) indicates that phosphorus is in its solid state.
Neon: Ne(g) - The (g) signifies that neon is in its gaseous state.
Chlorine: Cl₂(g) - The (g) indicates that chlorine exists as a diatomic gas, with the formula Cl2, in its standard state.
Iron (Fe):
Iron is a chemical element commonly found in its solid state under standard conditions. The chemical symbol for iron is Fe, which is derived from the Latin word "ferrum." Iron is a lustrous, silvery-gray metal and is known for its strength and ability to be magnetized. In its standard state, iron exists as a solid, denoted by the (s) symbol. Therefore, the complete chemical formula for iron in its standard state is Fe(s).
Phosphorus (P):
Phosphorus is an element that exists in various forms, with the most common form being a solid known as white phosphorus. Under standard conditions, white phosphorus is the most stable and prevalent form. It is a waxy, white-to-yellowish solid that is highly reactive and combustible. The chemical symbol for phosphorus is P, and it is represented by the (s) symbol to indicate its solid state. Therefore, the complete chemical formula for phosphorus in its standard state is P(s).
Neon (Ne):
Neon is a chemical element that exists as a gas under standard conditions. It is a noble gas and is known for its bright red-orange glow when used in signs and lighting. Neon is chemically inert, meaning it does not readily react with other substances. The chemical symbol for neon is Ne, and it is represented by the (g) symbol to indicate its gaseous state. Therefore, the complete chemical formula for neon in its standard state is Ne(g).
Chlorine (Cl):
Chlorine is a halogen element that exists as a diatomic gas under standard conditions. It is a highly reactive and corrosive substance with a yellowish-green color and a pungent odor. Chlorine exists as a molecule with two chlorine atoms bonded together, forming Cl₂. The (g) symbol is used to indicate that chlorine exists as a gas. Therefore, the complete chemical formula for chlorine in its standard state is Cl₂(g).
Learn more about chemical formula from the link given below.
https://brainly.com/question/32018188
#SPJ2
Which of the following alkyl halides will react fastest with CH3OH in an SN1 mechanism?
A) I B) II C) III D) IV
Answer:
IV
Explanation:
The complete question is shown in the image attached.
Let us call to mind the fact that the SN1 mechanism involves the formation of carbocation in the rate determining step. The order of stability of cabocations is; tertiary > secondary > primary > methyl.
Hence, a tertiary alkyl halide is more likely to undergo nucleophilic substitution reaction by SN1 mechanism since it forms a more stable cabocation in the rate determining step.
Structure IV is a tertiary alkyl halide, hence it is more likely to undergo nucleophilic substitution reaction by SN1 mechanism.
The rearrangement which most likely occurs in the following reaction can be described as a
HBr
(CH3)2CHCH=CH2 →
a. hydride shift from C-2 to C-1.
b. hydride shift from C-3 to C-2.
c. proton shift from C-2 to C-1.
d. methyl group shift from C-3 to C-2.
Answer:
b. hydride shift from C-3 to C-2.
Explanation:
Markovnikov's rule states that *in the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents* (wikipedia).
This rule implies that the hydrogen of HBr will be attached to C-1 and the carbocation will be on C-2. Remember that the order of stability of carbocations is tertiary > secondary > primary > methyl. A hydride shift can yield a tertiary carbocation.
C-3 is a tertiary carbon atom. If the hydride on carbon 3 shifts to carbon 2, a tertiary and more stable carbocation is formed. This accounts for the major product in the reaction.
PLEASE HELP QUICK!
Your organ systems do not function
independently. Consider the following
scenarios, and explain how different
organ systems are working together.
a) You step on hot pavement in the
summer and quickly pull your foot
back.
(b) after running up the stairs you
breathe a little harder.
(c) A friend has a cold, and three days
later you have a cold too.
Answer:A
Explanation:
Your muscular system is at work
Uncontrolled energy:
A. Produces order
B.causes destruction
C. Can make things
D. Can do useful work
Answer:
B
Explanation:
uncontrolled energy damage the body
Answer: causes destruction
Explanation:
Which describes the number of protons in the atom of a particular element
Answer:
Atomic Number
Explanation:
The number of protons an atom has is unique to that element. The number of protons is noted as the atomic number for that element on the periodic table.
What is the motion of the particles in this kind of wave?
A hand holds the left end of a set of waves. The waves themselves make a larger set of waves in the same direction as that of the smaller waves. A label Wave motion is above the series of waves and an arrow next to the label points right.
The particles will move up and down over large areas.
The particles will move up and down over small areas.
The particles will move side to side over small areas.
The particles will move side to side over large areas.
Answer:
D
Explanation:
The particles will move side to side over large areas.
Answer:
The particles will move side to side over large areas.
Explanation:
Which of the following salts will be less soluble in 0.10 M NaCl than it is in pure water?
PbF2
CaCO3
All of the options are less soluble in 0.10 M NaCl than in pure water.
PbCl2
The less soluble salt : PbCl₂
Further explanationGiven
0.1 M NaCl
Required
The less soluble salt
Solution
If we see from the answer option, the salt that is more difficult to dissolve in NaCl is PbCl₂ because it has the same ion (Cl)
When PbCl₂ is dissolved in water, ionization will occur
PbCl₂ ⇒ Pb²⁺+ 2Cl⁻
So, when dissolved in NaCl, NaCl itself will be ionized
NaCl ⇒ Na⁺ + Cl⁻
Based on the principle of equilibrium, the addition of an ion (one of the ions is enlarged), the reaction will shift towards the ion that was not added. In addition to this Cl ion, the reaction will shift to the left so that the solubility of PbCl₂ will decrease (the reaction to the right decreases)
Acids are substances that surround us in our everyday life. The uses of acids range from providing essential nutrients for our bodies to dissolving metals. Some acids are safe to handle with our bare hands or even use in food preparation. Other acids will severely burn human skin. Why these substances can all be acids and yet have such different properties?
Answer: Strong and Weak Acids
Explanation:
Acids, also known as electrolytes, are compounds that break down into cations (positively charged ions) and anions when dissolved in water (negatively charged ions). Solid Electrolytes (Acids) fully ionize,
Whereas weak electrolytes (acids) only partly ionize.
I REALLY NEED HELP can someone help me please I’ll mark you brainliest! :)
Answer:
A
Explanation:
Strontium-90, a radioactive isotope with applications in medicine, has a half-life of approximately 30 years. Out of a 100-gram sample, approximately how much remains after 170 years? 2 grams 8 grams 17 grams 81 grams
There are 2 grams remain
Further explanationGiven
t1/2 = 30 years
t = 170 years
No = 100 g
Required
Remaining sample
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt Nt=100.\dfrac{1}{2}^{170/30}\\\\Nt=1.969\approx 2~grams[/tex]
A solution of sulfuric acid (H2SO4, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the sulfuric acid
Answer:
0.0705 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1
The mole ratio of the base, NaOH (nB) = 2
Next, data obtained from the question. This include the following:
Volume of acid, H₂SO₄ (Va) = 25 mL
Volume of base, NaOH (Vb) = 34.55 mL
Molarity of base, NaOH (Mb) = 0.1020 M
Molarity of acid, H₂SO₄ (Ma) =?
The molarity of the acid, H₂SO₄ can be obtained as follow:
MaVa / MbVb = nA/nB
Ma × 25 / 0.1020 × 34.55 = 1/2
Ma × 25 / 3.5241 = 1/2
Cross multiply
Ma × 25 × 2 = 3.5241
Ma × 50 = 3.5241
Divide both side by 50
Ma = 3.5241 / 50
Ma = 0.0705 M
Therefore, the concentration of the acid, H₂SO₄ is 0.0705 M
Answer:
C=0.140964M
Explanation:
M1V1=M2V2
DATA
M1=?
M2=0.1020M
V1=25.00ML
V2=34.55ML
M*25.00ML=(0.1020M)*(34.55ML)
M*25.00ML=3.5241M*ML
M=3.5241M*ML/25.00ML
M=0.140964M
Therefore, concentration of sulfuric acif is 0.140964M
If you ingest a chemical from lab, immediately drink plenty of milk, then contact your instructor and wait for his/her response.
a. True
b. False
Answer:
False
Explanation:
The correct answer would be false.
If a chemical is ingested while working in the lab, the correct thing to do would be to contact the lab instructor right away as eating or drinking of any kind is prohibited in the laboratory.
While drinking milk may help in some cases depending on the nature and amount of the chemical ingested, only the lab instructor has the technical know-how to analyze the situation and administer first aids. Milk has the capacity to act as a buffer in some cases pending the time the victim would be able to get adequate medical attention.
g calculate the quantity of energy produced per gram of uranium 235 for the neutron induced Fusion of uranium
Answer:
Energy released by 1 g of U-235 = 7.603 * 10¹⁰ J
Explanation:
Uranium-235, U-235 undergoes neutron-induced fission to give the following products:
1 neutron + ²³⁵U --> ¹⁴¹Ba + ⁹²Kr + 3 neutrons
Masses of reactants and products:
neutron = 1.009 amu, uranium-235 = 235.044 amu, Ba-141 = 140.910 amu, Kr-92 = 91.910 amu
mass defect = mass of reactants - mass of products
mass defect = (235.044 + 1.009) - (140.910 + 91.910 + 3 * 1.009)
mass defect = 236.053 - 235.847 = 0.206 amu
1 amu = 1.6 * 10⁻²⁷ kg
Using E = mc²
E = 0.206 * 1.6* 10⁻²⁷ kg * (3 * 10⁸ m/s)² = 2.966 * 10⁻¹¹ J
therefore, 1 atom of U-235 releases 2.966 * 10⁻¹¹ J of energy
energy released by 1 g of U-235 can be calculated as follows:
1 mole or 253 g of U-235 contains 6.02 * 10³ atoms
1 g of U-235 will contain 6.02 * 10³/235 = 2.563 * 10²¹ atoms
Energy released by 1 g of U-235 = 2.563 * 10²¹ * 2.966 * 10⁻¹¹ J = 7.603 * 10¹⁰ J
How many Joules are required to raise the temperature of 4.66 g of CCl4 from 20.9◦C to 76.8◦C?
The specific heat capacity of CCl4 is 0.856 J/g◦C.
Heat required to raise temperature : 224.02 J
Further explanationGiven
mass CCl4 = 4.66 g
Δt= 76.8 - 20.9 =55.9 °C
c = The specific heat capacity of CCl4 = 0.856 J/g◦C.
Required
Heat /energy required
Solution
Heat can be formulated
Q=m.c.Δt
[tex]\tt Q=4.66\times 0.86\times 55.9\\\\Q=224.02~J[/tex]
How many protons are in an element with an atomic number of 8 and mass number of 18
Answer:8
Explanation:
Atomic number = 8
Mass number = 18
The number of protons and the number of electrons is equal to the atomic number.
The number of neutrons in the nucleus is given by the difference in mass number and atomic number.
So, number of protons are 8
number of electrons = 8
number of neutrons = 18 - 8 = 10
Which statements describe density? Check all that apply.
O Density is a chemical property of an object.
O The density of an object is constant.
O Density is a derived unit of measure.
D Density is the sum of the mass and volume of an object.
I The density of an object determines whether it will sink or fioat.
Answer:
2,3,5
Explanation:
Got correct on EDG
18.2 mL of a 0.156 M solution of lead(II) nitrate are added to 26.2 mL of a 0.274 M solution of potassium iodide.
What is the mass of the Pbl2 precipitate formed in the reaction Pb(NO3)2 (aq) + 2 KI (aq) - Pbl2 (s) + 2 KNO3? The molar mass of Pbly is 461.0 g/mol.
Provide your answer in units of grams, with the correct number of significant digits. Enter your answer as a number only; do not include units.
The mass of the Pbl2 : 1308.87
Further explanationGiven
18.2 mL of a 0.156 M Pb(NO3)2
26.2 mL of a 0.274 M KI
Reaction
Pb(NO3)2 (aq) + 2 KI (aq) - Pbl2 (s) + 2 KNO3
Required
the mass of the Pbl2
Solution
mol Pb(NO3)2 = 18.2 x 0.156 = 2.8392 mlmol
mol KI = 26.2 x 0.274 =7.1788 mol
Limiting reactant Pb(NO3)2(smaller ratio of mol : reaction coeffiecient)
mol Pbl2 based on limiting reactant (Pb(NO3)2)
From equation, mol ratio of Pb(NO3)2 : Pbl2 = 1 : 1, so mol Pbl2=mol Pb(NO3)2=2.8392
Mass Pb(NO3)2 :
[tex]\tt mass=mol\times MW\\\\mass=2.8392\times 461\\\\mass=1308.87~grams[/tex]
Which of the following conditions favor the SN1 mechanism as opposed to the SN2 mechanism?
I. tertiary alkyl halide
II. primary alkyl halide
III. polar solvent
a. only I
b. only Il
c. I and Ill
d. Il and Ill
Answer:
c. I and Ill
Explanation:
SN1 mechanism is a unimolecular nucleophillic substitution reaction mechanism. "Unimolecular" implies that only one molecule is involved in the rate determining step and that is the alkyl halide. The rate determining step of SN1 reaction is the formation of a carbocation which subsequently reacts with a nucleophile in the fast step.
SN1 reactions occur mostly with tertiary alkyl halides due to sterric reasons. SN2 mechanism involves a crowded transition state because it is a concerted reaction mechanism. This is not possible in a tertiary alkyl halide due to the presence of bulky groups around the tertiary carbon atom hence tertiary alkyl halides do not undergo nucleophilic reaction by SN2 mechanism.
Secondly, polar solvents aid in the ionization of the alkyl halide thus assisting in the formation of the carbocation which participates in the second step of the reaction.
Ethanol has the chemical formula C2H5OH. Write and balance the chemical reaction for the combustion of ethanol
Answer:
C2H5OH(l)+3O2(g)⟶2CO2+3H2O(l)
Explanation:
The balanced equation for the combustion of ethanol will be
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]. According to this carbon dioxide and water will be the product.
What is combustion?
Combustion is a chemical process during which a material reacts quickly with oxygen and generates heat.
The original substance is referred to as the fuel, and the supplier of oxygen is referred to as the oxidizer. The fuel can be solid, liquid, or gas, but it is usually a liquid for airplane propulsion.
Combustion is a chemical reaction between two or more substances, usually involving oxygen, that produces light and heat in the form of a flame.
The products of complete ethanol combustion are carbon dioxide and water, as well as the start releasing of light and heat.
The equation will be:
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]
Thus, in this way, the combustion of ethanol occurs.
For more details regarding combustion, visit:
https://brainly.com/question/15117038
#SPJ2
Deuterium is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. The chemistry of deuterium is nearly identical to the chemistry of hydrogen, except that C−D bond is slightly (5.0KJ/mole) stonger than the C−H bond. Reaction rates tend to be slower if a C−D bond as opposed to a C−H bond is broken in a rate limiting step. This effect on the rate is called a kinetic isotope effect.
a. True
b. False
Answer:
True
Explanation:
We know that the zero-point-energy of a C-D system is quite lower than the zero point energy of the C-H bond so the C-D bond is stronger.
Kinetic isotope effect refers to the change in the rate of reaction owing to a change of one of the atoms of the reactants by replacing it with one of its isotopes.
Since we know that the C-D bond is stronger than the C-H bond, when we replace hydrogen with deuterium in a reaction's rate determining step we experience a little lag in the rate of reaction. This is referred to as the kinetic isotope effect in physical organic chemistry.
if you are using a formula where you need the change in temperature, explain why it is not important whether your temperatures are both in Kelvin or Celsius?
Answer:
This is because, Kelvins and Celcius degrees both agree at fixed points i.e; the lower fixed point and upper
Perform the following calculations and report each answer with the correct number of significant figures.
628 × 342 b. 5.45 – 2.3 c. 28.0/13.483
d. 14.98 + 27,340 + 84.7593
Answer:
a)215000
b) 3.2
c) 2.08
d) 27439.74
Explanation:
Significant figures:
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.
b) 5.45 -2.3
3.2
d) 14.98 + 27,340 + 84.7593
27439.74
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
a) 628 × 342
214776
we will round off this value into 3 significant figures.
215000
c) 28.0/13.483
2.08