Explanation:
I think the answer is B and A
What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
4
Explanation:
Since there are 3 carbons on the left side, make the coefficient of CO2 equal to 3.
Also, since there are 8 hydrogen on the left side, make the coefficient of H2O equal to 4.
This means there are 3(2)+4=10 oxygen atoms on the right, making the coefficient of O2 equal to 5.
Effective collisions are those that result in a chemical reaction. In order to produce an effective collision, reactant particles must possess some minimum amount of energy. This energy, used to initiate the reaction, is called the activation energy.