ATOMS

Question 1

Rutherford’s experiment

Answer 1

• First proposed existence of a + charged nucleus
• Bombarded piece of gold foil with + charged alpha particles, most pass straight through, some deflected backwards
  = Majority of atom is empty space with small dense nucleus at centre.

Question 2

Thompson’s experiment

Answer 2

• 1890s, discovered cathode rays
• Cathode rays attracted towards + electrode, shows particles have - charge
• particles called the electron

Question 3

Mass number

Answer 3

(A)
- No. protons and neutrons

Question 4

Atomic number

Answer 4

(Z)
- No. of protons and electrons
- Identity of the element
- Position of element in periodic table

Question 5

Neutrons

Answer 5

• Atomic number - Mass number
• Mass = 1
• Charge = 0

Question 6

Protons

Answer 6

• Atomic number
• Mass = 1
• Charge = +1

Question 7

Electrons

Answer 7

• Atomic number
• Mass = 0
• Charge = -1

Question 8

What is an isotope

Answer 8

Atoms of the same elements with diff mass numbers

2 or more isotopes with same number protons, diff number neutrons

Question 9

Relative isotopic mass

Answer 9

The mass of 1 atom of that isotope compared to 1/12th of the mass of carbon-12

Question 10

Relative atomic mass

Answer 10

Average mass of the atom that includes different isotope abundances compared to 1/12th the mass of carbon -12

Question 11

Relative atomic mass formula

Answer 11

(Isotope abundance x isotope mass number) / 100