Base isolation is a method of earthquake resistant engineering where a structure is separated from the ground by isolation units that reduces the impact of seismic vibration energy. So, the last answer choice would be the best definition.
When the reaction equation is:
HF ↔ H+ + F-
and when the Ka expression
= concentration of products/concentration of reactions
so, Ka = [H+][F-]/[HF]
when we assume:
[H+] = [F-] = X
and [HF] = 0.35 - X
So, by substitution:
6.8 x 10^-4 = X^2 / (0.35 - X) by solving for X
∴ X = 0.015 M
∴[H+] = X = 0.015
when PH = -㏒[H+]
∴PH = -㏒0.015
= 1.8
The answer is (4) 4. Germanium is a main group element in group 4A. Therefore, like carbon, it has 4 valence electrons in the ground state.
A displacement reaction (also known as a replacement reaction) is when one element is replaced by another compound. Ex) Fe+CuSO4=FeSO+Cu
