Odd, unusual, or unexpected.
A is Ea, which stands for activating energy. Energy is needed to get the reaction underway and Ea is the energy needed to “start” the reaction.
B is the temperature either released or absorbed.
The diagram shows that the reaction is exothermic based on the fact that the products energy is lower than the reactants. That is because energy (which is temperature in this case) is released during the process. If the reactants would have been lower than the products, the reaction would be endothermic.
Properties of metals:
High melting points
High density
Ductile
Malleable
Good conductors of electricity
Good conductors of heat
I think if you added a proton you would have chlorine.
The noble gasses are the he chemical elements in group 18 of the periodic table. The gasses in this family include helium, neon, argon, krypton, xenon, and radon. All these gasses are colorless are oderless, elements in this family have atoms with a full outer shell of electrons. They are also called inert gasses.
Six valence electrons
Answer: 
atoms of hydrogen are there in
35.0 grams of hydrogen gas.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
1 mole of hydrogen 
= 
atoms
17.5 mole of hydrogen = 
atoms
There are atoms of hydrogen are there in
35.0 grams of hydrogen gas.
