Answer:
Electromagnetic Force
Explanation:
Every aspect of chemical reaction is the output of electromagnetic force though the forces can take on many forms because of the quantum wave nature of particles.
The electromagnetic force has the ability to attract opposite charges such as protons and electrons and it repels same charges such as electrons and protons.
This force is an important force in the chemical reaction as it it is responsible for bonding between atoms. Though other forces are unique in their own way but they don't affect chemical reaction. Force of gravity is not strong enough to affect chemical reactions; when nuclear forces are involved in a reaction, such reaction is a nuclear reactor; not chemical reaction.
One of the roles of the electromagnetic force in chemical reaction is that it holds the electrons that are in the outer orbit around the nucleus; this, in the long run creates bonds with other chemical elements to create a visible matter.
Answer:
D) With an increase in altitude, atmospheric pressure increases as well.
Explanation:
Generally when altitude increases, the value of pressure decreases. This shows that pressure is inversely proportional to altitude. For example, the higher the altitude, the lower the pressure and vice versa. At very high altitude, the number of molecules of air are smaller than the number of moles of air at very low altitude. Thus, the higher the altitude, the lower the atmospheric pressure and the lower the altitude, the higher the atmospheric pressure. Therefore, option (D) is false.
Answer: 
Explanation:
Electron gain enthalpy is defined as energy released on addition of electron to an isolated gaseous atom.
The amount of energy released will be maximum when the tendency to attract electrons is maximum. As flourine has atomic number of 9 and has electronic configuration of 2,7. It can readily gain 1 electron to attain stable noble gas configuration and hence liberates maximum energy.
6.4mole•64.06g/1mole=409.98g
