By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other. Often we can work out how and where they lived, and use this information to find out about ancient environments. Fossils can tell us a lot about the past.
A. Boiling water is an example of physical change, whereas digesting food, breaking glass, and shoveling snow are not.
Answer: It was known as the SPACE RACE.
Explanation: The space race was a cold war between the Soviet Union (USSR) and the United States (US), to get satellites and humans into space. The competition began in earnest on August 2, 1955, when the Soviet Union responded to the US announcement. On April 12, 1961, the USSR surprised the world again by launching Yuri Gagarin into a single orbit around the Earth in a craft they called Vostok 1.
The aggregation state, or state of aggregation, is the form of the substance in different kinds of states. For example, Bromine could occur as solid, liquid or gas. For all these forms, its molecular aggregation is diatomic in nature. It is always written as Br₂.
It's 3. There are two Cl in the reactants and 3 in the products, and they need to be balanced/equal. Only way to do that is add three on the left side, which will give you 6 Cl (3×2Cl) and then 2 on the other side, which will also give you 6 Cl (2×3Cl)