Answer:
Because of the less reactivity of copper.
Explanation:
As well as being resistant to the elements and thereby less likely to be affected by rainfall, hail, and mildew than other types of roofing, copper is also one of the most fireproof materials available. Copper is also highly resistant to thermal changes and thereby doesn't deteriorate quickly.
Magnesium would also corrode PDQ. Magnesium sheeting would also pose an unacceptably high fire hazard.
Answer:
A decrease in [H3O+] and an increase in pH (option a)
Explanation:
Equilibrium of water is shown in this equation
2H₂O ⇄ H₃O⁺ + OH⁻
When you add NaOH, you are modifying [OH⁻]
NaOH → Na⁺ + OH⁻
In equilibrium of water, the [OH⁻] increases
2H₂O ⇄ ↓ H₃O⁺ + OH⁻ ↑
As the [OH⁻] increases, by Le Chatellier, the equilibrium tends to decrease [H₃O⁺].
If the [OH⁻] is higher, pH is also high so the solution of water and sodium hydroxide would be totally basic.
Answer: Trade winds :)
Explanation: just took the test
Answer :
121.5 <span>
μCi
Explanation : We have Ce-141 half life given as 32.5 days so if the activity is 3.8 </span><span>μci after 162.5 days of time elapsed we have to find the initial activity.
We can use this formula;
</span>

3.8 /

=

((0.693 X 162.5 ) / 32.5) = 121.5
<span>
On solving we get, The initial activity as 121.5 </span>μci