1. Atomic Structure and The Periodic Table

Question 1

What was stated in Dalton’s
atomic theory? (4)

Answer 1

● Atoms are tiny particles made of elements
● Atoms cannot be divided
● All the atoms in a element are the same
● Atoms of one element are different to those of
other elements

Question 2

What did Thompson discover
about electrons? (3

Answer 2

What did Thompson discover about electrons?
● They have a negative charge
● They can be deflected by electromagnetic
fields
● They have very small mass

Question 3

Explain the current model of
the atom

Answer 3

Explain the current model of the atom
● Protons and neutrons are found in the nucleus
● Electrons orbit the nucleus in shells
● The nucleus is tiny compared to the total volume of
atom
● Most of atom’s mass is in the nucleus
● Most of the atom is empty space between the nucleus
and the electrons

Question 4

What is the charge of a proton
and an electron

Answer 4

Proton = +1
Electron = -1

Question 5

Which particle has the same
mass as proton

Answer 5

Neutron

Question 6

Which two particles make up
most of an atom’s mass

Answer 6

Protons and neutrons

Question 7

How to calculate the number
of neutrons

Answer 7

mass number -
atomic number

Question 7

What does the atomic number
show about an element

Answer 7

Atomic number = number of protons in
an atom

Question 8

How is mass number
calculated?

Answer 8

number of protons +
number of neutrons

Question 9

Define the term, isotope.

Answer 9

Define the term, isotope.
Atoms of the same element with different
number of neutrons and therefore
different mass number

Question 10

Why do different isotopes of
the same element react in the
same way? (2)

Answer 10

Neutrons have no impact on the chemical
reactivity
● Reactions involve electrons, isotopes have
the same number of electrons in the same
arrangement

Question 11

Define relative atomic mass

Answer 11

The weighted mean mass of an atom of
an element compared with one twelfth of
the mass of an atom of carbon

Question 12

Define relative isotopic mass

Answer 12

Define relative isotopic mass
The mass of an atom of an isotope
compared with one twelfth of the mass of
an atom of carbon-12

Question 13

The relative isotopic mass is
same as which number?

Answer 13

Mass number

Question 14

What two assumptions are
made when calculating mass
number?

Answer 14

1. Contribution of the electron is neglected
2. Mass of both proton and neutron is taken as 1.0 u