Question

4
which of these earth features is most important for life to exist?
a. earths size and gravity.
b. earths atmosphere made of silicon oxide.
c. earths wide range of surface temperatures.
d. earths magnetic field that blocks harmful rays from the sun.

2
about how much of earths air is nitrogen and oxygen?
a. mostly nitrogen (78%) and some oxygen (21%).
b. half oxygen (50%) and some nitrogen (30%).
c. mostly carbon dioxide (78%) and some oxygen (21%).
d. all oxygen (100%).

3
why is earths liquid iron core and its magnetic field important for life?
a. it helps oxygen stay in the lower air.
b. it pushes away space rocks.
c. it helps attract the suns heat.
d. it protects earth from harmful radiation from the sun.

4
what is the most important reason earth can support life, when considering its place in space?
a. how long it takes earth to go around the sun.
b. how far earth is from the sun.
c. how far the sun is from other stars.
d. what earths moon is made of.

Explanation:

• Question 1: Earth's atmosphere is crucial. Silicon oxide is incorrect (atmosphere is mainly gases like nitrogen and oxygen). A wide range of temps isn't the most vital. Magnetic field is protective but atmosphere (which has oxygen for respiration) is key.
• Question 2: Earth's air has mostly nitrogen (78%) and some oxygen (21%).
• Question 3: Liquid iron core and magnetic field protect from harmful solar radiation.
• Question 4: Earth's distance from the Sun (Goldilocks zone) is key for liquid - water existence (important for life).

Answer:

1. A.
2. A.
3. D.
4. B.