Answer:
Hennig Brand
Explanation:
Which tool could be used to measure the mass of a rock?
A. Measuring cup
B. Digital thermometer
C. Triple-beam balance
D. Graduated cylinder
what is the most massive object in our solar system
A substance that dissolves another substance is a _____________________
A. Solvent
B. Solute
Answer:
b it is easy its b
Explanation:
Answer:
B
Explanation:
The technetium-99 isotope has a half-life of 6.0 hours. If 100.0 mg were injected into a
patient how much remains after 18 hours?
Answer:
12.5mg of technetium-99 remain
Explanation:
When a radioactive isotope decays in the time, its concentration follows the equation:
ln[A] = -kt + ln[A]₀
Where [A] could be taken as the mass of radioactive isotope after time t (18h),
k is rate constant = ln 2 / Half-Life = ln 2 / 6hours = 0.1155hours⁻¹
[A]₀ is initial amount of the isotope = 100.0mg
Replacing:
ln[A] = -0.1155hours⁻¹ *18hours+ ln[100.0mg]
ln[A] = 2.5257
[A] =
12.5mg of technetium-99 remain
350 coulombs of charge flows through an iron in 70 seconds. What is the current flowing through the iron
MAGNESIUM (Mg)
+FLUORINE (F) =
Answer:
MgF2 magnesium fluoride
Magnesium has 12 electrons. How many electrons will be orbiting in the outermost shell, farthest away from the nucleus?
1) 2
2) 10
3) 8
4) 4
5) 3
6) 7
Answer:
Magnesium has an outer energy level of n=3 with two electrons in in its energy level. Therefor Magnesium has 2 valance electrons.
Explanation:
which type of circuit has a string of lights and one light goes out but the others stay lit
Answer:parrallel
Explanation:
What is happening to the energy storage molecules in the plants and humans in the space station?
Answer:
Answer is in photo
Explanation:
When we mix water and sugar then they made
Question 6 of 10
What is an anode?
A. The electrode that is oxidized in a galvanic cell
B. The solution inside a salt bridge
C. The electrode that is reduced in a galvanic cell
D. The electrolytes around an electrode
SUBMIT
Answer:
I believe the answer is A, sorry if i'm wrong
Explanation:
Factors that affects properties of a solution
hi can someone help me quickly please its for chemistry
Answer:
Explanation:
The atom X has 1 1 protons (atomic number) and thus would have 11 electrons. This means the atom X would have 1 valence electron in it's outermost shell. While the atom Y has 17 protons (atomic number) and thus would have 17 electrons. This means the atom Y would have 7 electrons in it's outermost shell.
The type of bond this atoms (X and Y) would form is an Ionic (or electrovalent) bond. This bond/combination involves the transfer of electron(s) and a molecule is not formed as seen in the image below.
Name 8 ways why landfill is bad for earth
Answer:
1.Creates environmental hazards
2.Can contribute to global warming processe
3.Can pollute harmful and toxic things in the air
4.has harmful gases that can hurt the environment including the water and soil
5.A waste of space that is taking up the earth
6.full of rubbish and toxins that can effect the environment
7.can hurt humans and animals because of the toxic chemicals produced in the air
8.Make the land soil weaker because of the bad toxins and chemicals
A radioisotope forms a stable isotope after it undergoes radioactive decay. Which is the best conclusion to draw from this statement?
A. It undergoes alpha decay. B. It undergoes beta decay. C. It does not participate in a decay series. D. It does not have a long half-life.
Answer:
C. It does not participate in a decay series.
Explanation:
From this statement, we can deduce that a radioisotope that forms a stable isotope after it undergoes radioactive decay suggests that it does not participate in a decay series.
It could have emitted any form of radioactive particles which can be alpha or beta. We do not know if it has a long or short half life because the value is not given. But since the radioactive decay in one step produces a stable isotope, we can conclude that it did not participate in a decay series. A decay series involves a radioactive decay in multiple steps.Answer:
C
Explanation:
because that's just the answer:)
As an electron in an atom moves from the ground state to the excited state, the electron...?
Answer:
Absorbs energy
Explanation:
As an electron in an atom moves from the ground state to the excited state, the electron absorbs energy.
Electrons moves around in permissible orbits around the nucleus of an atom.
An electron in a certain energy level has a definite amount of energy associated with it at that level. When an electron in ground state absorbs energy, it moves to a higher energy level. When an electron in excited state loses energy, it moves to a lower energy level.The transition of electrons from one level to another involves loss or gain of energy.
The atmospheric pressure is highest at...
Answer: Sea Level
Explanation: facts
13. When compared with the blood in the arteries,
the blood in the veins...
1 does not move at all
2 is under lower pressure
3 contains more gases
4 contains more water
Answer:
is under lower pressure
Explanation:
I think because arteries is for oxygenated blood so it flows very fast and the pressure is big but for veins , it is for deoxygenated blood that flows slower than oxygenated blood, so of course the pressure is lower.
2020.is crazy
2021 is_____??!?!?
Answer:
zany
Explanation:
Answer:
a fresh start
Explanation:
How many moles do you have in 17.23 grams of Cu(SO4)2
Answer:
0.06739 mol Cu(SO₄)₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
17.23 g Cu(SO₄)₂
Step 2: Identify Conversions
Molar Mass of Cu - 63.55 g/mol
Molar Mass of S - 32.07 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Cu(SO₄)₂ - 63.55 + 2(32.07) + 8(16.00) = 255.69 g/mol
Step 3: Convert
[tex]17.23 \ g \ Cu(SO_4)_2(\frac{1 \ mol \ Cu(SO_4)_2}{255.69 \ g \ Cu(SO_4)_2} )[/tex] = 0.067386 mol Cu(SO₄)₂
Step 4: Check
We are given 4 sig figs. Follow sig fig rules and round.
0.067386 mol Cu(SO₄)₂ ≈ 0.06739 mol Cu(SO₄)₂
Based on the information in the table, which two elements are most likely in the same group, and why?
Based on the replacement reaction, what would the products of the reaction be?
BeSO4 + 2NH4OH → Be(
)2 + (NH4)2SO4
BeSO₄ + 2NH₄OH → Be( OH)₂ + (NH₄)₂SO₄
Further explanationGiven
Reaction
BeSO₄ + 2NH₄OH → Be( ...)₂ + (NH₄)₂SO₄
Required
The products
Solution
There are two possible displacement reactions
Single replacement if one element replaces or reduces another element in the compound and forms a new compound
A + BC ⇒ AC + B
Double replacement if both the cations and anions of the two compounds in the reactant swap positions to form 2 new compounds in the product
AB + CD ⇒ AD + CB
Thus, the product is Be(OH)₂
Answer:
OH
Explanation:
describe Bohr’s model of the atom consisted of a central
surrounded by electrons moving in specific
Answer:
The answer to this question is given below in the explanation section.
Explanation:
The Bohr model depicts an atom as a small, positively charged nucleus surrounded by electrons.These electrons travel in circular orbit around the nucleus similar in structure to the solar system,except electrostatic forces rather than gravity provide attraction.Electron orbit around the nucleus resembles that of planets around the sun in the solar system.
The Bohr model was an improvement on the earlier cubic model(1902),the plum pudding model(1904) the saturnine model (1904) the rutherford model (1911) since the Bohr model is a quantum physics based modification of the Rutherford may source combine the two:the Rutherford-Bohr model
Although revolutionary at the time,the Bohr model is a relatively primitive model of the hydrogen atom compared to the valence shell atom.As an initial hypothesis it was derived as a first order approximation to describe the hydrogen atom.Due to its simplicity and correct results for selected systems.
In 913 Bohr suggested that electrons could only have certain classical motions:
Electrons in atoms orbit the nucleus.The electrons can only orbit stably,without radiating in certain orbits at a certain discrete set of distances from the nucleus.These orbit are associated with definite energies and are also called energy shells or energy levels.Electrons can only gives or lose energy by jumping from one allowed orbit to another,absorbing or emitting electromagnetic radiation with a frequency (v) determined by the energy difference of the levels according to the plank relation.when an atom gains a valence electron, it become a (n)_____ion.
An atom that gains electrons and becomes negatively charged is known as an anion.
Hope it helps!
calculate the enthalpy for the reaction D + F = G + H using
G + C = A + B deltaH = 277
C + F = A delta H = 303
D = B + H delta H = -158
The enthalpy for the reaction : ΔH = -132
Further explanationGiven
Reaction and the enthalpy
Required
the enthalpy
Solution
Hess Law
Reaction 1 reverse :
A + B = G + C ΔH = -277
Reactions 2 and 3 remain the same (unchanged)
C + F = A ΔH = 303
D = B + H ΔH = -158
Add up all the reactions and remove the same compound from two different sides
D + F = G + H ΔH = -132
how many molecules are in 4Li2SO4?
Answer:
4
The molecule here is LiSO4, because the definition of a molecule is 2 or more molecules chemically bound together. A coefficient of 4 is another way of saying "4 molecules of LiSO4"
2) How does matter change? That was a question students were
investigating in class. Each group had an experiment to carry out and
then determine if the changes observed indicated a physical or
chemical change. Here is one groups experimental procedure and
results.
Before
Mix
Aler
ALS
1000 m
vinegar
84
Rowe
1000 ml
solution
34
Rece
84
RP
23c
Changing
Tempe
Temper
Temperature
What type of change occurred? Cite any appropriate evidence.
A)
Chemical; the Alka-Seltzer tablet dissolved and
disappeared.
B)
Chemical; nothing new was formed.
C)
Chemical; a gas was produced and the temperature
changed.
D)
Physical; the Alka-Seltzer tablet dissolved and
disappeared.
To protect against a fire, copper used for wiring in a house would best be covered with
Plastic or rubber as non metal are bad conductor of electricity.
If energy absorbed is less than energy emitted does temperature increase or decrease?
Answer:
temperature increases energy
Describe what is ionic bonding and how it happens.
Answer:
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
Explanation:
Answer:
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
Explanation: