GCSE Atomic Structure & Periodic Table 3

Question 1

Carbon-12 and Carbon-14 are isotopes. Which statement correctly compares them?

Accepted Answer

Carbon-14 has 2 more neutrons than Carbon-12

Answer

Both have 6 protons; Carbon-12 has 6 neutrons and Carbon-14 has 8 neutrons, a difference of 2.

Question 2

Which of the following is a property of Group 7 elements (halogens)?

Accepted Answer

They have 7 electrons in their outer shell

Answer

Halogens have 7 outer-shell electrons and need one more to complete their shell, making them reactive non-metals.

Question 3

An ion has 10 electrons and a charge of 2+. How many protons does it have?

Accepted Answer

12

Answer

A 2+ charge means the atom lost 2 electrons, so protons = electrons + 2 = 10 + 2 = 12 (magnesium).

Question 4

As you move down Group 1 (alkali metals), reactivity with water:

Accepted Answer

Increases

Answer

Reactivity increases down Group 1 because the outer electron is further from the nucleus and more easily lost.

Question 5

Which electron shell can hold a maximum of 8 electrons?

Accepted Answer

Both second and third shells

Answer

The second and third shells each hold up to 8 electrons at GCSE level.

GCSE - General Certificate of Secondary Education Practice Test