1. 12
2. oxygen
3. hydrogen, Manganese?, phosphorus, all other elements
4. silicon
5. all living things would die because all living things need oxygen, if there were little oxygen everything would die.
1. oxygen, carbon, hydrogen
2. calcium
3. 23%
4. magnesium, potassium, sulfur, sodium
5. it would be difficult to function and your body would struggle to maintain homeostasis as there will be too much of an element and it will be harmful to you.
