GCSE Combined Science Chemistry

Question 1

What is the relative charge of a proton?

Accepted Answer

+1

Answer

A proton has a relative charge of +1 and a relative mass of 1. Protons are found in the nucleus of an atom alongside neutrons (which have no charge). The number of protons defines the element (atomic number).

Question 2

Which of the following substances has a giant covalent structure?

Accepted Answer

Diamond

Answer

Diamond has a giant covalent structure where each carbon atom is bonded to four others in a tetrahedral arrangement. This creates a very strong, rigid lattice, which is why diamond is extremely hard and has a very high melting point.

Question 3

What is produced when a metal reacts with an acid?

Accepted Answer

Salt + hydrogen

Answer

When a metal reacts with an acid, a salt and hydrogen gas are produced. For example: magnesium + hydrochloric acid → magnesium chloride + hydrogen. This is a key reaction type for GCSE Chemistry.

Question 4

In the periodic table, what name is given to the elements in Group 7?

Accepted Answer

Halogens

Answer

Group 7 elements are called halogens. They include fluorine, chlorine, bromine, iodine, and astatine. Halogens are reactive non-metals that form salts when they react with metals — the name 'halogen' means 'salt-former'.

Question 5

What happens to the mass of a substance when it is burned in an open container?

Accepted Answer

The mass may appear to decrease because gaseous products escape

Answer

In an open container, gaseous products (like carbon dioxide and water vapour) escape into the air, so the measured mass appears to decrease. In a closed system, the total mass would remain the same, as stated by the law of conservation of mass.

GCSE Revision Practice Test

GCSE Revision Practice Test

GCSE Combined Science Chemistry