Answer:
The structures in the cell work together to perform its life functions
Explanation:
Atomic Mass is equal to the sum of the number of protons and neutrons.
Thus the atomic mass = 3 + 4
= 7
Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is
and one anion whose chemical symbol is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cation is formed by the metal sodium which forms
and the anion is formed by non metal chlorine which forms
.
For a formula unit of sodium chloride, the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus
and
combine to form neutral 
I remember coming across this question and the options were:
KOH, HCN, NH₃, HI, Sr(OH)₂
Now, a substance with a low pH is one that dissociates completely in water to release hydrogen ions, while basic substances dissociate completely to release hydroxide ions. Therefore, in the order of increasing pH:
HI, HCN, NH₃, Sr(OH)₂, KOH