1. Movement in the Solar System

2. Can you explain ? Why do day and night happen on Earth ?
What is a year ?
What is a month ?

3. Why do day and night happen ?
The Earth continually spins around on its axis.
On the side which is facing the sun it is day-time.
On the side which is facing away from the sun it is night-time.
day
night
Earth’s axis

4. What is a year ?
A year is the time it takes for the Earth to orbit the sun once.
This is 365 and ¼ days.
We add an extra day every fourth year to deal with the ¼ days. This is a leap year.

5. What is a month ? There are a number of meanings for the word month.
Roughly, it is the time taken for the moon to orbit the Earth once ( days ).