No. Magnesium, and Bromine are a chemical compound when put together.
Neither Bromine, nor Magnesium react with any sort of water.
Answer: D) helium.
Explanation:
Nuclear fission is a process which involves the conversion of a heavier nuclei into two or more small and stable nuclei along with the release of energy.

Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.
Example: 
Thus when deuterium and tritium , the two isotopes of hydrogen are fused, a heavier nuclei helium is being formed from two smaller nuclei releasing a neutron.
The answer is going to be mercury
In order to emit electrons, the cesium will have to absorb photons. Each photon will knock out one electron by transferring its energy to the electron. Therefore, by the principle of energy conservation, the energy of the removed electron will be equal to the energy of the incident photon. That energy is calculated using Planck's equation:
E = hf
E = 6.63 x 10⁻³⁴ * 1 x 10¹⁵
E = 6.63 x 10⁻¹⁹ Joules
The electron will have 6.63 x 10⁻¹⁹ Joules of kinetic energy
<span>Opening a can of paint requires a screwdriver or other machine to pry open the lid. The screwdriver affect the force applied to opening the lid. The answer is : </span><span>B. It increases the applied force and changes its distance and direction.</span>