Answer:
Magnetic fields and Electric fields
Explanation:
D. Matter and energy are the same.
Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy 
is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
for forward reaction is (40-30) = 10.
Families are another names for the columns
Answer:
12*2*6.022*10^23. Atoms of hydrogen.
Explanation:
First of all if u know that 1 molecule of calcium hydroxide contain 2 hydrogen atom and 1 mole of calcium hydroxide contain 6.022*10^23 molecules of calcium hydroxide.
Hence 1 mole of calcium hydroxide contain 2*6.022*10^23 atom of hydrogen.
So 12 mole of calcium hydroxide contain =12*2*6.022*10^23. Atoms of hydrogen.
