1.1 Atomic structure

Question 1

Who are the three scientists that developed an atomic model in order.

Answer 1

.John Dalton
.J.J Thomson
.Ernest Rutherford

Question 2

What was Daltons three part Atomic theory?

Answer 2

.All substance are made of atoms-Atoms cannot be created, divided or destroyed.
.Atoms of the same element are alike and atoms of different elements are different
.Atoms join together to make new substances

Question 3

What discovery caused the original Dalton model of an atom to change?

Answer 3

The subatomic particle

Question 4

How did JJ Thomson discover the electron?

Answer 4

He experimented with a cathode ray tube

The beam moved towards the positively charged plate so he knew that particles must have a negative charge

Question 5

Describe the atomic model proposed by JJ Thomson

Answer 5

.Plum Pudding model

Negatively charge electrons scattered through a positively charged material

Question 6

What did Ernest Rutherford discover from his gold foil experiment?

Answer 6

.Most of the particles shot straight through suggesting that an atom is mostly empty space
.A few particles were deflected and a few bounced back showing there must be a tiny dense positively charged Nucleus

Question 7

Describe Rutherford’s new model of the atom

Answer 7

.Mass is concentrated in the central nucleus
.Mostly empty space
.Electrons travel in random paths around the nucleus

Question 8

Describe the structure of an atom

Answer 8

.Small central nucleus made up of protons and neutrons

.Electrons orbit the nucleus in cells

Question 9

What are the relative masses of the subatomic particles?

Answer 9

Proton-+1
Neutron-0
Electron- -1

Question 10

What are the relative masses of the three subatomic particles?

Answer 10

Proton= 1
Neutron-1
Electron= 1/1836

Question 11

Why do atoms contain an equal number of protons and electrons?

Answer 11

The charges cancel out as atoms are neutral

Question 12

Compared to the rest of the atom, how large is the nucleus?

Answer 12

It is very small

Question 13

Where is most of the mass concentrated in an atom?

Answer 13

The Nucleus

Question 14

Give the equation to work out the mass number

Answer 14

Number of Protons+Neutrons

Question 15

What are Isotopes?

Answer 15

.These are different atoms of the same element containing the same number of protons but different numbers of neutrons in their nuclei

Question 16

What does the Atomic number allow you to calculate?

Answer 16

Number of protons

Question 17

How would you calculate the number of neutrons

Answer 17

Mass number-Atomic number

Question 18

How does the existence of Isotopes results in the relative atomic mass of some elements not being whole numbers?

Answer 18

.Different number of neutrons
.RAM is calculated using an abundance of isotopes and because it is an average it can lead to it not being a whole number

Question 19

How do you calculate the R.A.M of an element from their relative masses and isotopes?

Answer 19

(mass of isotope-A x % of isotope-A) + (mass of isotope-B x % of isotope-B)
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