Answer:
с
Explanation:
the first quantum number of an electron gives the information about the energy level the electron is in
Answer:
C
Explanation:
Br + Br-> Br2 (covalent bond)
bond formation releases energy, as the Br's are in a lower energy state like Br2
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.
STEM is an acronym meaning
Science
Technology
Engineering
Mathematics
One of the main focuses of STEM courses is on science, so you will be learning about various types of science
This is an approach at learning to have students learn all four types of subjects in one class, based on real world applications.
Distilled water has the a neutral ph. Pure water always has a ph of 7.