Answer:
B. A chemical change occurred which caused the liquid's physical properties to change.
Explanation:
The reduction of the temperature of the system meant that the reaction absorbed heat energy from it. This shows that a chemical reaction was in progress. New products were formed, and this is proved by the change in the color to blue.
If its oxidised, water and carbon dioxide is formed.
When heat is added, particles move faster.
D - block elements in a periodic table are also known as transition metals.
Answer:
1. 4
Explanation:
there are four atoms of hydrogen. you can tell because there is a 4 after the H.