Topic 1: Formulae, Equations and Amount of Substance

Question 1

what is an atom

Answer 1

single particle, smallest part of an element

Question 2

what is an element

Answer 2

atom or group of atom of only one type, it cannot be broken down into smaller substances

Question 3

what is an ion

Answer 3

electrically charged atom that lost or gained an electron

Question 4

what is a molecule

Answer 4

2 or more atoms chemically combined

Question 5

what is a compound

Answer 5

2 or more elements chemically joined

Question 6

what is empirical formulae

Answer 6

smallest whole number ratio of atoms of each element in a compound or molecule

Question 7

molecular formula

Answer 7

the actual number of atoms of each element in a compound or molecule

Question 8

what is the a mole

Answer 8

measuring unit of the amount of substance

Question 9

what number is used for the relative mass of atom

Answer 9

carbon-12

Question 10

what is relative atomic mass (Ar) and how do we calculate it

Answer 10

the average mass if an element in comparison to 1/12th of the map of carbon 12. it is the bigger number on periodic table

Question 11

how do we calculate relative molecular mass of molecules

Answer 11

add mass of each element and multiply by number of atoms

Question 12

what is the Avogadro constant and what does it apply to?

Answer 12

the number of particles equivalent to the relative atomic mass or molecular mass of a substance. it applies to atoms, molecules, ions and electrons

Question 13

what is the value of Avogadro constant?

Answer 13

6.023 x 10^23 mol-1

Question 14

what is 1 mole equal to

Answer 14

6.023 x 10^23 mol-1

Question 15

how do you find no. of mole when mass is involved formula

Answer 15

n=mass (g)/mr

Question 16

how do u find number of particles when you know the number of mole

Answer 16

n=no.of particle/6.023^23
so rearrange- no. of particle= 6.023^23 x no. of mole