Answer:
Step-by-step explanation:
Life cycle describes the cycle of life. Life goes through different stages over time. It starts with birth and ends with death. But the cycle re-starts and the end becomes the beginning.
Changes in matter describes matter in different states. An example is water - when you are hot, you want ice to chill down. Ice is water in solid form. When you are thirsty, you want to drink liquid water. When it is cold outside, the warm steam from a hot bowl of soup feels so good. Steam is water in gas form.
pH (acids & bases) is a measure of acidity. Orange juice you drink is very acidic and has a low pH. Even though soda does not taste like acid, it is mildly acidic and has a pH under 7. Soap you use to wash hand is a base and have a high pH above 7.