Select the two chemical reactions that adhere to the law of conservation of matter. A

2As + 6 NaOH → 2 Na3AsO3 + 2H2

B

2H2O2 → 2H2O + O2

C

NaBr + Cl2 → 2NaCl + Br2

D

Zn + 2HCl → ZnCl2 + H2

E

8Ag2S → 10Ag + S8

F

Ba3N2 → 2Ba + N2

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

i think its 5049.

i hope this !

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.