1. Na3PO4+Mg(NO3)2= NaNO3 + MgPO4
So this is not the answer.
2. Al+CuCl2= AlCl3+ Cu
So this is the answer.
3. Mg+O2= MgO2
So this is not an answer
4. Cl2+KI= KCl+I2
So this is also an answer
Hence B and C are answers
Answer: polar molecule.
Explanation:
The boiling point is the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid. The boiling point is dependent on the type of forces present.
Iodine monochloride (ICl) is a polar molecule due to the difference in electronegativities of iodine and chlorine. Thus the molecules are bonded by strong dipole dipole forces. Thus a higher temperature is needed to generate enough vapor pressure.
Bromine 
is a non polar molecule as there is no electronegativity difference between two bromine atoms. The molecules are bonded by weak vanderwaal forces and thus has low boiling point.
Light energy into chemical energy
Answer:
The number of positive charges in nucleus of an atoms are equal to the atomic number and also positive charges are equal to the negative charges which are electrons in neutral atom.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e⁻
Mass= 9.10938356×10⁻³¹ Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Neutron and proton:
Neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P⁺
Symbol of neutron= n⁰
Mass of proton=1.672623×10⁻²⁷ Kg
Mass of neutron=1.674929×10⁻²⁷ Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.
The total number of elements that one particular element can bond to can be determined by simply drawing the Lewis structure of the element.
Place the chemical symbol
Then look at the group number = valence electrons
Distribute the valence electrons around the atom.
C = 4 bonds
N = 3 bonds
O = 2 bonds
