Answer:
1.
2.
Explanation:
1.Momentum is given as the product of mass by velocity of an object.
Momentum,
m=1,500kh, v=6m/s

2.Momentum,
m=7800kg, v=30m/s

new mass=7800+800=8600
As mass is increased, so does the resultant velocity as mass is directly proportional to velocity.

 
        
             
        
        
        
2. Rubidium
3. Antimony
4. Ytterbium
5. Einsteinium
        
             
        
        
        
The molecular weight of a given compound would simply the
sum of the molar weights of each component.
 
The molar masses of the elements are:
C = 12 amu
H = 1 amu
N = 14 amu
O = 16 amu
where 1 amu = 1 g / mol
 
Since there are 6 C, 5 H, 1 N and 2 O, therefore the
total molecular weight is:
molecular weight = 6 (12 amu) + 5 (1 amu) + 1 (14 amu) +
2 (16 amu)
molecular weight = 123 amu
 
Therefore the molecular weight of nitrobenzene is 123 amu
or which is exactly equivalent to 123 g / mol.
 
        
             
        
        
        
Cu⇒ 1 atom
N⇒2 atoms
O⇒6 atoms
Total 9 atoms
<h3>Further explanation  </h3>
The empirical formula is the smallest comparison of atoms of compound forming elements.  
A molecular formula is a formula that shows the number of atomic elements that make up a compound.  
<em>(empirical formula) n = molecular formula  </em>
Chemical formula : Cu(NO₃)₂
Number of Cu : 1
Number of N : 2
Number of O = 2 x 3 = 6
Total atoms in Cu(NO₃)₂ : 1 + 2 + 6 = 9
 
        
             
        
        
        
Answer:
B
Explanation:
When water is at the surface of the ground, it evaporates and goes back to the clouds for which causes it to rain therefore returning water back.