GCSE Atomic Structure & Periodic Table 4 â Questions and Answers
Question 1: Which of the following describes the nucleus of an atom?
- Large, negatively charged, and low density
- Small, positively charged, and very dense (Correct answer)
- Large, positively charged, and low density
- Small, negatively charged, and very dense
Correct answer: Small, positively charged, and very dense
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?
- 3
- 4
- 6 (Correct answer)
- 8
Correct answer: 6
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?
- They have 7 outer electrons
- They readily form compounds
- They have a full outer electron shell (Correct answer)
- They are highly reactive metals
Correct answer: They have a full outer electron shell
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�
- 2,8,2
- 2,8 (Correct answer)
- 2,6
- 2,8,4
Correct answer: 2,8
Mg has configuration 2,8,2; losing 2 electrons gives Mg²⺠a configuration of 2,8.
Question 5: What evidence from the alpha particle scattering experiment led to the nuclear model of the atom?
- Most alpha particles were deflected through large angles
- A small number of alpha particles were deflected or bounced back (Correct answer)
- All alpha particles passed straight through the gold foil
- Alpha particles were absorbed by the gold foil
Correct answer: A small number of alpha particles were deflected or bounced back
A small fraction bouncing back suggested a tiny, dense, positively charged nucleus that could repel the positive alpha particles.
Question 6: As you descend Group 7 (halogens), the colour of the elements:
- Gets lighter
- Gets darker (Correct answer)
- Stays the same
- Changes from metallic to non-metallic
Correct answer: Gets darker
Fluorine is pale yellow, chlorine is green, bromine is red-brown, and iodine is dark grey/purple â progressively darker.
Question 7: Which particle in an atom has negligible mass and a negative charge?
- Proton
- Neutron
- Electron (Correct answer)
- Nucleon
Correct answer: Electron
Electrons have a relative mass of approximately 1/1836 (essentially 0) and carry a charge of â1.
GCSE Atomic Structure & Periodic Table 4
Which of the following describes the nucleus of an atom?