Atomic structure exam q

Question 1

Define atomic number 1 mark

Answer 1

Atomic number is the total number of protons and electrons in the nucleus of an atom

Question 2

Explain why atoms of the same element may have different mass numbers 1 mark

Answer 2

They have different numbers of neutrons in their nucleus even if they have the same number of protons and electrons(

Question 3

Define the term relative atomic mass 1 mark

Answer 3

Weighted mass of an element and its isotopes compared to 1/12th of an atom of carbon 12

Question 4

Explain why the first ionisation energy of krypton is higher than that of bromine 1 mark

Answer 4

Krypton has a higher number of protons in the nucleus than bromine however they both have the same number of electrons in their outer shell

Question 5

Explain why the first ionisation energy of aluminum is less than the first ionisation energy of Mg

Answer 5

Because the outermost electrons of aluminum are in a 3p subshell whereas the outermost electrons of magnesium are in a 3s subshell
3p is higher in energy than 3s

Question 6

State the element in Period 3 that has the highest melting point.
Explain your answer
3 marks

Answer 6

Silicon
Explanation= Because silicon contains covalent bonding which requires the highest amount of energy to break, also there is many covalent bonds