Gallum: Z = 31
electron configuration: [Ar] 4s^2 3d10 4s2 4p1
Highest energy electron: 4p1
Quantum numbers: 
n = 4, because it is the shell number
l = 1, it corresponds to type p orbital  
ml = may be -1, or 0, or +1, depending on space orientation, they correspond to px, py, pz
ms = may be -1/2 or +1/2, this is the spin number.  
        
             
        
        
        
Answer:
An atom is made of up subatomic particles called protons, neutrons and electrons. The center of an atom is called the nucleus and is where the protons and neutrons are held while electrons orbit the nucleus in orbital shells. A electron has a negative charge, a proton has a positive charge, and a neutron has no charge (neutral).
The atomic number of a atom is the total amount of the atom's protons. In a neutral atom (Not an ion), the amount of electrons is the same as the protons. Therefore, the atomic number also tells the amount of electrons in the atom.
A ion is a negatively or positively charged particle due to the giving or taking of electrons with one or more atoms (Called an ionic bond). An atom that gives away electrons becomes positively charge because that atom now has more protons than neutrons. An atom that takes an electron becomes negatively charge because that atom now has more electrons than protons.
Atomic Mass is the sum of an atom proton and neutrons. To determine how many neutron an atom has, subtract the atomic mass from the atomic number. Electrons do not play a part in atomic mass as their mass is  1/1,836 of a proton's mass.
A isotope is two or more forms of the same element that contain equal amounts of protons but different amount of neutrons.
 
        
             
        
        
        
The pairs are:
K, Kr - Same period
Be, Mg - Same group
Ni, Tc - Both are transition metals
B, Ge - Both are metaloids
Al, Pb - Both form inert oxides
        
             
        
        
        
Remember, look at the coefficients in the balanced equation! Here are three mole ratios:
1 mole<span> N2 / </span>3 moles<span> H2.</span>
3 moles<span> H2 / 2 moles NH3.
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