Answer:
1). In the periodic table as suggested by Mendeleev, elements were
the periodic table as suggested by Mendeleev, elements werearranged in the order of increasing atomic number.
--> T
2). Sodium (Z=11) is a member of a group called alkaline earth
Sodium (Z=11) is a member of a group called alkaline earthmetals.
--> T
3). Elements to the extreme right of the periodic table are metals.
--> F
They are non-metals .
4). Metalloids have properties of metals and non-metals.
--> T
If C6H6 was the molecular formula, what is the empirical formula?
Answer:
so the empirical formula for benzene is also CH.
Explanation:
What is the percent composition of Ca(C2H3O2)2?
Select one:
a) 25.3% Ca, 30.4% C, 3.8% H, 40.5% O
b) 40.4% Ca, 24.2% C, 3.1% H, 32.3% O
c) 6.67% Ca, 26.67% C, 40.0% H, 26.67% O
d) 12.5% Ca, 25% C, 37.5% H, 25% O
Answer:
A
Explanation:
RMM of ca(c2h302)2=158
%Ca= 40/158×100=25.3
%C=48/158×100=30.3
%H=6/158×100=3.7
%O=64/158×100=40.5
Answer:
a) 25.3% Ca, 30.4% C, 3.8% H, 40.5% O
Explanation:
Molar mass of Ca(C₂H₃O₂)₂ = 158.160 g/mol
percent composition:
Ca = (40 /158.160 ) × 100
Ca = 25.3%
C = (48 /158.160 ) × 100
C = 30.4%
H = (6 /158.160 ) × 100
H = 3.8%
O = (64 /158.160 ) × 100
O = 40.5%
40.5% + 3.8% + 30.4% + 25.3% = 100%
It means 1st option is correct.
what element is found on the left side of the periodic table
Answer:
Mostly Metals, But hydrogen is the only one that isn't.
Why is the C-O bond considered to be polar?
The molecule is symmetrical.
The electronegativity difference of the atoms in the bond.
Answer:
The electronegativity difference of the atoms in the bond.
Explanation:
Carbon is electropositive while Oxygen is highly electronegative, hence highly polar due to strong intermolecular forces.
The molecule is not symmetrical because it's dipole moments don't cancel out.
How many molecules of oxygen are produced when a sample of 38.9 g of water is decomposed by electricity?
A) 6.5 x 10^23
B) 1.3 x 10^24
C) 2.6 x 10^24
D) 2.3 x 10^25
Answer:
A) [tex]6.5\times 10^{23}\ \text{molecules}[/tex]
Explanation:
m = Mass of water = 38.9
M = Molar mass of water = 18 g/mol
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}\ \text{mol}^{-1}[/tex]
The reaction of electrolysis would be
[tex]2H_2O(l)\rightarrow 2H_2(g)+O_2(g)[/tex]
Number of moles of [tex]H_2O[/tex]
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{38.9}{18}\ \text{mol}[/tex]
From the reaction it can be seen that 2 moles of [tex]H_2O[/tex] gives 1 mole of [tex]O_2[/tex]
So, number of moles of [tex]O_2[/tex] produced is
[tex]\dfrac{38.9}{18}\times \dfrac{1}{2}=1.081\ \text{mol}[/tex]
Number of molecules
[tex]1.081N_A=1.081\times 6.022\times 10^{23}\\ =6.5\times 10^{23}[/tex]
So, [tex]6.5\times 10^{23}\ \text{molecules}[/tex] of oxygen is produced.
GIVE REASON:-
Ammeter is connected in series and voltmeter is connected in parallel to the electric load in an electric circuit .
Answer:
An ammeter is a device that is used to measures the amount of current flowing in a circuit and a voltmeter measure electric potential difference in an electric circuit between two points.
An Ammeter is connected in series because of its low resistance capacity and it will be connected in parallel it can get damaged due to high current. A voltmeter is connected in parallel in an electric circuit because the potential difference remains the same when connected in parallel.
The boiling point of chlorine (Cl2) is 171.6 K. Which of the
following best predicts the boiling point of iodine (12)?
Answer:
The boiling point of iodine is 363.7°F / 184.3°C
Which of the following has no electrical charge?
Select one:
a. proton
b. neutron
c. electron
Answer:
neutron
Explanation
neutrons have no net charge
Molar mass for C 3 H 6 (O H)2
Answer:
The answer is 76.0944
Explanation:
I hope this helps!
The molar mass and molecular weight of C3H6(OH)2 is 76.0944.
help asap
1.How many significant figures are present in the following measurements? solve these
a. 52.10 mL
b. 6.07∙10100 atoms
c. 300 km
2.List the number of protons, neutrons, and electrons present in a Mg atom.
3.Draw a Bohr diagram for an atom of Mg.
4.Calculate the number of moles in 162.32 g of CuCl2
Answer: As we all are aware that life on Earth is existed due to several environmental changes and there are several scientific factors of sustainability that support the survival and evolution of life on Earth.
Scientific factors of sustainability include solar energy, chemical cycle, and biodiversity that supported life on Earth. solar energy helps all organism and especially producers to gain energy and store the energy which further used in chemical cycles of transferring energy to other trophic levels.
Chemical cycle also involves the interaction of biotic and abiotic envrionment with each other that leads to environmental changes as well as organisms adapt themselves accordingly.
Biodiversity maintains the balance in the ecosystem and prevent dominancy of one organism otherwise it can lead to scarcity and organism would not be able to survive. Variation in biodiversity due to random mating in the same species leads to evolution and produces new species of organisms.
Hence, scientific factors of sustainability play major role in survival and evolution of life on the Earth.
Explanation: Is this what you need
Plastic is used to cover the copper wire in the power codes of appliances because plastic differs from copper in _________. 1. Destiny 2. Hardness. 3. Phrase at room temperature 4. Electrical conductivity
Answer:
Bro, its so obvious. Its electrical conductivity.
Explanation:
Plastic is an insulator thus it can protect conducting material from shortage of current as well for the safety of users. Thus, option 4 is correct.
What is conductivity ?Conductivity of a material is the measure of its ability to pass electric current through it. Based on this there are three types of materials namely conductors, insulators and semiconductors.
Conductors are materials highly conducting at room temperature. Semiconductors are not conducting at room temperature but can be conducting at higher temperatures.
Insulators does not conduct electricity at any situation. Hence, insulators are used to coat conducting wires and to protect from electric shock. Plastic s an insulator which can cover conducting copper wire for safety. Thus, option 4 is correct.
Find more on conductivity:
https://brainly.com/question/15085692
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Diamond has a density of 3.26 g/cm^3. What is the mass of a diamond that has a volume of 25 cm^3?
Answer:
81.5 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 25 × 3.26
We have the final answer as
81.5 gHope this helps you
define liquor ammonia
Answer:
ammonia water especially : the impure solution obtained as a by-product in destructive distillation (as of coal, tar, and bones)
Explanation:
Answer:
liquor ammonia is the ammonia water especially , the impure solution obtained as a by-product in destructive distillation (as of coal, tar, and bones)
Which reproductive structure is correctly paired with its functions
Answer:
(4) sperm - transports genetic material
Explanation:
Which reproductive structure is correctly paired with its function'?
(1) uterus - usual site of fertilization
(2) testis - usual location for egg development
(3) ovary - delivers nutrients to the embryo
(4) sperm - transports genetic material
Solution:
The uterus (also known as the womb) is where the fertiled egg (foetus) stays until it is ready to be delivered. The usual site of fertilization is the fallopian tube.
The testis is responsible for the production of sperm and hormones. The uterus is where the egg development takes place.
The ovary is responsible for the production of egg and hormones. The embryo receives nutrient through the fetus.
The sperm transports genetic material to the ovum.
Answer:
4
Explanation:
because ovaries def do not deliver nutrients to the embryo thats the placenta and the testis are DEF not a site for egg development and the uterus is not where fertilization happens i believe its where the fetus is kept and therefore the only correct answer is 4 :)
2. Look at the chemical formula of a compound below. Use the periodic table to
answer the following question.
NH4
Which elements are found in this compound? (6.5A)
F. Nitrogen and Hydrogen
G. Nitrogen and Helium
H. Nickel and Hydrogen
J. Nickel and Helium
Which describes a stationary reference point?
A. A slower moving truck from the point of view of a car passing it
B. A plan from the point of view a falling sky driver
C. A tree from the point of view of someone in a moving car
D. The sun from the point of view of someone sitting outside
Answer: C
Explanation:
two answer multiple choice-- please help!
Study the reaction.
NH4+ + NO2– ⟶ N2 + 2H2O
The rate of this reaction is proportional to the concentration of ammonium (NH4+) and the concentration of nitrogen dioxide (NO2–).
What is the rate law of this reaction?
Rate = K[NH4+][NO2–]
Rate = K[N2][H2O] ^2
Answer:
Rate = K[NH₄⁺][NO₂⁻]
Explanation:
In kinetics studies of reaction, rate law is a mathematical expression that relates speed of reaction with concentrations of the reactants. For a reaction:
aA + nN → cC + dD
The rate law is expressed in terms of [A] and [B] as follows:
Rate = K[A]ᵃ[N]ⁿ
Where K is rate constant.
For the reaction:
NH4+ + NO2– ⟶ N2 + 2H2O
The rate law is:
Rate = K[NH₄⁺][NO₂⁻]As was said in the problem, the rate is porportional to [NH₄⁺] and to [NO₂⁻]
Which of the following is an example of a chemical property?
a. color
b. density
c. phase
d. the ability to rust
What is the medium of the wave shown in the paragraph?
Answer:
The water is the medium of the wave
The atoms in NaOH are:
Sodium, oxygen, and hydrogen
Naquida, oxygen, and hydrogen
Naoline and Oxyhydrous
Nitrogen, Argon, Oxygen, and Hydrogen
Answer:
Sodium, Oxygen and Hydrogen
Explanation:
Na= Sodium
O= Oxygen
H= Hydrogen
Which of the following greenhouse gasses does not contribute to climate change
The options are;
A) Carbon dioxide
B) Carbon Monoxide
C) Chloro fluoro carbon and methane
D) Refrigerant Freon
Answer:
B) Carbon Monoxide
Explanation:
Greenhouse gases are compounds available in the atmosphere which are capable of absorbing infrared radiation, thereby making heat in the atmosphere to be trapped and held there. The most common ones are carbon Monoxide, carbon dioxide, chloro-fluoro carbon, methane, nitrous oxide, ozone and freon. Out of them, the one that is the most dangerous and doesn't contribute to climate change is carbon monoxide because it is a silent killer gas
Thus, option B is correct
What is the evidence that Mars once had flowing liquid water? Why is this important?
Answer:
New findings from NASA's Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars. Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.
Explanation:
Why is Argon (Ar} in group 18, period 3 on the periodic table ?
A.
B.
C.
D.
Answer:
B
Explanation:
All elements on group 18 are noble gases, which noble gases are in fact actually not highly reactive due to the large amount of valence electrons located on the out shell.
What type of chemical reaction is: CH4 + 202® CO2 + 2 H2O
Answer:
Incomplete combustion - carbon monoxide and water.
Explanation:
What is the correct name for H3AsO3
Answer:
arsenous acid
Explanation:
All living organisms are composed of
OA. at least three cells.
ОВ.
one or more cells.
OC. at least 100 cells.
OD. only one cell.
Answer:
B
Explanation:
all living things are composed of one or more cells
4.
How does a positive ion form?
Answer: Metal atoms lose electrons from their outer shell when they form ions: the ions formed are positive, because they have more protons than electrons.
A serving of Frosted Flakes cereal contains 235,000 J of energy. Calculate the change in temperature (ΔT) that would occur if this food was used to heat 1,000 grams of water.
Answer:
55.95K
Explanation:
its obtained from Q=MCT where
Q-amount of heat
M-mass of water
C-specefic heat capacity of water
T-change in temperature
Classifying Characteristics of Rocks
Answer:
The texture of a rock is a result of its mineral composition
Most rocks contain more than one type of sediment
Explanation:
Which is the correct electron configuration for the element nitrogen
Answer: 1s²2s²2p³ or it can also be 3s²2p³