atoms and equations

Question 1

what is an atom?

Answer 1

the smallest particle of a chemical element

Question 2

relative charges of proton, neutron, and electron

Answer 2

proton + 1
neutrons 0
electrons -1

Question 3

the relative mass of proton, neutron, and electrons

Answer 3

proton 1.0
neutron 1.0
electron 1/2000

Question 4

what is a mass number?

Answer 4

number of protons + neutrons

Question 5

what is the atomic number?

Answer 5

number of protons

Question 6

what is a relative atomic mass?

Answer 6

the mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 7

what is a relative formula mass?

Answer 7

Mr of a molecule

Question 8

the formula for relative atomic mass

Answer 8

(isotope mass x abundance) / 100

Question 9

On the periodic table, the mass number of magnesium is given as 24.31. Why is this not an integer?

Answer 9

The mass number on the periodic table is the relative isotopic mass. 2 or more isotopes of magnesium contribute to this mass number

Question 10

formula for finding mole?

Answer 10

mass/mr

Question 11

formula for mass in terms of moles

Answer 11

moles x mr

Question 12

what is the mole?

Answer 12

the amount of a substance that contains the same number of atoms or particles as 12g of carbon-12

Question 13

value of Avogadro’s constant

Answer 13

6.02 x 10 to the power of 23

Question 14

formula for concentration

Answer 14

moles/volume

Question 15

the formula for percentage yield

Answer 15

(actual yield/theoretical yield) x 100%

Question 16

importance of percentage yield

Answer 16

tells us the % of our reactants have been converted into products

Question 17

formula for volume

Answer 17

24 x moles

Question 18

the formula for atom economy

Answer 18

(mass of desired products/mass of all products) x 100%

Question 19

importance of atom economy

Answer 19

can reduce chemical waste, make the reactions more sustainable by minimizing waste and maximizing efficiency

Question 20

what is concentration?

Answer 20

how much solvent is dissolved in a given volume of solvent

Question 21

formula for moles in terms of concentrations and volume

Answer 21

volume x concentration

Question 22

the formula for ideal gas

Answer 22

pV = nRT

Question 23

oxidation in terms of electrons

Answer 23

loss of electrons

Question 24

reduction in terms of electrons

Answer 24

gain electrons

Question 25

what is a redox reaction?

Answer 25

reaction where both oxidation and reduction occur where electrons are transferred

Question 26

what is an element?

Answer 26

a substance that cannot be broken down into smaller parts or changed into another substance

Question 27

what is a compound?

Answer 27

a substance that is made up of two or more different chemical elements that are combined in a fixed ratio, and held together by chemical bonds

Question 28

what is an isotope?

Answer 28

different forms of the same element, that have the same number of protons but a different number of neutrons

Question 29

what is a molecule?

Answer 29

2 or more atoms, held together by chemical bonds

Question 30

what is a mixture?

Answer 30

two or more substances that are not chemically combined together