SC3 - Atomic Structure ✓

Question 1

SC3a - Name the three base rules of atomic theory.

Answer 1

• All matter is made up of atoms
• Atoms cannot be broken down into smaller parts
• Atoms cannot be created or destroyed

Question 2

SC3a - Names the three subatomic particles as well as their relative mass and charge.

Answer 2

• Protons:
  
  • M: 1
  • C ⁺¹
• Neutron:
  
  • M: 1
  • C Neutral (0)
• Electron:
  
  • M: 1/1835 (negligible)
  • C ^-1

Question 3

SC3a - Describe the structure of an atom

Answer 3

• Protons and neutrons centred in a nucleus.
• Electrons orbiting outside in electron shells.

Question 4

SC3b - What did the Rutherford Gold foil test reveal about the space inside atoms?

Answer 4

Atoms are mostly empty spcae

Question 5

SC3b - What is an atomic number?

Answer 5

The number of protons in an atom. the bottom number on the symbol for an element

Question 6

SC3b - What is a mass number?

Answer 6

• The number of protons + neutrons in an atom (the mass).
• The top number on the symbol for an element.

Question 7

SC3c - What is an isotope?

Answer 7

Two atoms (of the same element) with the same atomic number but different mass numbers (amounts of neutrons)

Question 8

SC3c - What does the symbol A_r stand for and what does it mean?

Answer 8

• Relative Atomic Mass.
• The average mass of the naturally occurring form(s) of an element in relation to a Carbon-12 atom

Question 9

SC3c - How do you calculate the Ar of an element from the abundance of its isotopes.

Answer 9

(M₁ x A₁) + (M₂ x A₂) ^_(etc.) ÷ 100 (M=Mass A=Abundance)

Question 10

SC3c - Why does chlorine have a mass number with a decimal?

Answer 10

• It is its relative mass.
• There are two isotopes of chlorine, 35 and 37.
• Chlorine - 35 is more abundant than 37.