T cells and B cells are similar because they both deal with fighting of viruses.
Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:
t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at 
, 
A) For balanced chemical equation: 2HgO(s) → 2Hg(l) + O₂(g).
1) Mole ratio 1: n(HgO) : n(Hg) = 2 : 2 (1 : 1).
2) Mole ratio 2: n(HgO) : n(O₂) = 2 : 1.
3) Mole ratio 3: n(Hg) : n(O₂) = 2 : 1.
B) Balanced chemical equation: 4NH₃(g) + 6NO(g) → 5N₂(g) + 6H₂O(l).
1) Mole ratio 1: n(NH₃) : n(NO) = 4 : 6 (2 : 3).
2) Mole ratio 2: n(NH₃) : n(N₂) = 4 : 5.
3) Mole ratio 3: n(NH₃) : n(H₂O) = 4 : 6 (2 : 3).
4) Mole ratio 4: n(NO) : n(N₂) = 6 : 5.
5) Mole ratio 5: n(NO) : n(H₂O) = 6 : 6 (1 :1).
6) Mole ratio 6: n(N₂) : n(H₂O) = 5 : 6.
Answer: (3) The difference in electronegativity between carbon and oxygen is greater than that between fluorine and oxygen.
Explanation: Polarity of a molecule is due to the difference in electronegativity of the atoms. More is the electronegativity difference, more is the polarity.
Electronegativity of carbon = 2.5
Electronegativity of oxygen = 3.5
Electronegativity of fluorine = 4.0
Thus the difference in electronegativity of carbon and oxygen is=(3.5-2.5)= 1.0
Thus the difference in electronegativity of fluorine and oxygen is=(4.0-3.5)= 0.5.
Thus C-O bond is more polar than F-O bond.
