GCSE Atomic Structure & Periodic Table 4

Question 1

Which of the following describes the nucleus of an atom?

Accepted Answer

Small, positively charged, and very dense

Answer

The nucleus is tiny compared to the atom, contains protons and neutrons, and holds nearly all the atom's mass.

Question 2

An element X is in Period 3, Group 6 of the periodic table. How many outer shell electrons does it have?

Accepted Answer

6

Answer

The group number in the periodic table equals the number of electrons in the outermost shell.

Question 3

Which statement about noble gases (Group 0) is correct?

Accepted Answer

They have a full outer electron shell

Answer

Noble gases have a full outer shell (8 electrons, or 2 for helium), making them very stable and unreactive.

Question 4

Magnesium (atomic number 12) forms a 2+ ion. What is the electron configuration of Mg²⁺?

Accepted Answer

2,8

Answer

Mg has configuration 2,8,2; losing 2 electrons gives Mg²⁺ a configuration of 2,8.

Question 5

What evidence from the alpha particle scattering experiment led to the nuclear model of the atom?

Accepted Answer

A small number of alpha particles were deflected or bounced back

Answer

A small fraction bouncing back suggested a tiny, dense, positively charged nucleus that could repel the positive alpha particles.

GCSE - General Certificate of Secondary Education Practice Test