Answer:
H- hydrogen
Explanation: Hydrogen is in the first group meaning that it only has 1 valence electron and 1 energy level
10 is mixture of elements and compounds
11 is compound
12-15 are mixture of compounds
Answer:
Chlorine gas.
Explanation:
Hello!
In this case, the undergoing chemical reaction is:

Thus, given the moles of reacting both sodium and chlorine, we compute the moles of sodium chloride yielded by each reactant by considering the 2:2 and 1:2 mole ratios:

Thus, since chlorine yields less moles of sodium chloride, we infer it is the limiting reactant.
Best regards!
<em>Thermal energy</em> is the sum of the kinetic and potential energies of all the particles in an object.
Assume that you have 250 gL of water and 1 kg of water at the same temperature.
Then, each water molecule has the same kinetic energy.
The larger sample contains four times as many molecules, so it contains four times as much thermal energy.
Thus, thermal energy is directly proportional to mass.
In symbols, <em>KE </em>∝ <em>m</em> or <em>KE = km</em>.
The graph of a direct proportion is a <em>straight line passing trough the origin</em>.
It should look something like the graph below.