GCSE Qu's

Question 1

Why is an atom neutral?

Answer 1

The number of positive protons (+1) is equal to the number of negative electrons (-1). The charges cancel each other out.

Question 2

Why do simple molecular covalent substances have a low boiling/melting point or are liquid/gas at room temperature? (3)

Answer 2

Simple molecular covalent substances have weak forces of attraction between the molecules so only a low temperature/energy is needed to overcome this.

Question 3

Why do simple molecular covalent substances not conduct electricity?

Answer 3

There are no delocalised (free) electrons or free ions.

Question 4

Describe bonding in metallic structures (4)

e.g Gold

Answer 4

(USE DIAGRAM)

Giant regular uniform metallic lattice in uniform rows
Held together by strong electrostatic forces of attraction between the positive metal ions and the negative electrons
Positive metal ions in a ‘sea if delocalised electrons’