Answer:
13 years
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
Where;
t1/12 = half-life of Cobalt-60 = 5.3 years
t = time taken = the unknown
No = mass of radioactive material originally present = 5.2 g
N = mass of radioactive material at time t = 0.95 g
Substituting values;
0.693/5.3 = 2.303/t log (5.2/0.95)
0.131 = 2.303/t(0.738)
0.131 = 1.6996/t
t = 1.6996/0.131
t = 12.97 years
t = 13 years(to the nearest whole number)
Answer is: between the carbon atom and the oxygen atom in a molecule of methanal there are two (2) <span>pairs of electrons.
Methanal or formaldehyde (H</span>₂C=O)<span> </span><span>is the simplest of the </span><span>aldehydes.
In methanal, bond between carbon and oxygen is double covalent bond (one sigma and one pi bond), which means there are four shared electrons or two pair of electrons.</span>
Answer:
3rd option. 1–butanamine
Explanation:
To name the compound above, the following must be observed:
1. Locate the functional group in the chain. In this case the functional group is amine.
2. Locate the longest continuous carbon chain. This gives the parent name of the compound. In this case, the longest chain has 4 carbon i.e butane.
3. Since the functional group is amine, the parent name becomes butanamine i.e replacing the –e at the end in butane with –amine
4. Indicate the position of the functional group in the chain. In this case the functional group is at carbon 1
5. Name the compound by putting the above together.
The name of the compound is:
1–butanamine or butan–1–amine
pH decreases as the hydrogen ion concentration increases.
<u>Explanation:</u>
When there is a decrease in pH, that is pH decreases from 6 to 3 then the acidity increases.
That is the pH is between 1 to 7 then it is acidic
When the pH is 7 then it is neutral
When the pH is between 7 to 14 then it is basic
As the H⁺ ion concentration increases, then the pH value decreases, here pH decreases from 6 to 3.
So the concentration of Hydrogen ion increases, pH decreases.
<span>it tells you the sequence in which events occurred, not how long ago they occurred.</span>
