Answer:
17188 years
Explanation:
Recall the formula;
0.693/t1/2 = 2.303/t log(No/N)
t1/2 = half life of 14C
No = initial activity of 14C
N = activity of 14C at time t
t = age of the sample
Substituting values
0.693/5730= 2.303/t log(160/ 20)
1.21 * 10^-4= 2.0798/t
t = 2.0798/1.21 * 10^-4
t = 17188 years
Explanation:
In an ionic compound, there will be strong force of attraction between the combining atoms due to the opposite charges present on them.
For example, 
is an ionic compound where calcium has a +2 charge and each bromine atom has a -1 charge.
Therefore, in order to break the bond we need to provide more heat. Hence, boiling point of calcium bromide will be the highest.
is a covalent compound and as nitrogen is more electronegative in nature and also has a lone pair of electron hence, there will be a net dipole moment.
is also a covalent compound. And, as bromine is more electronegative than carbon atom so, dipole moment is in the outwards direction. Hence, in there will be zero dipole moment.
Therefore, its boiling is less than the boiling point of .
is a covalent compound and there will be no dipole moment.
Thus, we can conclude that given bromine-containing compounds are placed in their increasing boiling point order as follows.
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Answer:
Half-reactions:
Cr³⁺ + 1e⁻ → Cr²⁺; Zn → Zn²⁺ + 2e⁻
Net ionic equation:
2Cr³⁺ + Zn → 2Cr²⁺ + Zn²⁺
Explanation:
The Cr³⁺ is reduced to Cr²⁺:
<h3>
Cr³⁺ + 1e⁻ → Cr²⁺ -Half-reaction 1-</h3>
Zn is oxidized to Zn²⁺:
<h3>
Zn → Zn²⁺ + 2e⁻ -Half-reaction 2-</h3>
Twice the reduction of Cr:
2Cr³⁺ + 2e⁻ → 2Cr²⁺
Now this reaction + Oxidation of Zn:
2Cr³⁺ + 2e⁻ + Zn → 2Cr²⁺ + Zn²⁺ + 2e⁻
<h3>2Cr³⁺ + Zn → 2Cr²⁺ + Zn²⁺ - Net ionic equation</h3>
