Answer:
The answer is B. I took the test and made a 100
Explanation:
 
        
             
        
        
        
B) 6
one above one below and 2 on the left and right sides
        
                    
             
        
        
        
Answer:
Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. Noble gases are the least reactive of all elements. That's because they have eight valence electrons, which fill their outer energy level.
Elements: Argon
 
        
                    
             
        
        
        
Answer:
 0 kcal/mole
Explanation:
The most stable Newman projection corresponds to the minimum potential energy: Answer (e) 0 kcal/mole
 
        
             
        
        
        
Answer:
Number of protons = 82
Explanation:
Given data:
Atomic number of Pb = 82 
Mass number of Pb-207 = 207
Number of protons = ?
Solution:
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.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. 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.
Atomic number of Pb = number of protons or electrons 
82 = number of protons or electrons 
Mass number = Number of protons + number of neutron
207 = 82 + number of neutron
Number of neutrons = 207 - 82
Number of neutrons = 125