Answer:
The number of neutron in the Aluminium Isotope is :
B. 14
Explanation:
Isotopes : These are the atoms which have same atomic number but have different mass number.
<u>This image shows the average atomic mass of Al element because it is in decimals</u>.
Atomic mass = 26.98154
(Note : mass number of single isotope can never be in decimals)
It is the average of mass of different isotopes of Al
Major Isotopes of
are :
......atomic mass = 26
.......atomic mass = 27
mass of Al given in image(26.98) is nearly equal to mass of 2nd isotope(27)
mass of 
Now calculate the neutron in 
Number of neutron = mass number - atomic number
= 27 - 13
Number of neutron = 14
(Atomic mass is same as mass number)
Answer:
pH = 7.08
Explanation:
HCl ---------> H^+ + Cl^-
It's an acid, we are using this formula
pH = -log [H]^+
H^+ = 8.4 * 10^-8
pH = - log [8.4 * 10^-8]
It can also be solved as
-log 8.4-(-8log 10)
-0.924-(-8×1)
-0.924+8
7.076
To the nearest hundredth
pH = 7.08
By circle fraction additional number for the number
Here is your answer

REASON:
Elements which have 4 valence electrons are generally metalloids.
The metalloids show the properties of both metals and non-metals.
We know that,
no. of protons= Atomic number
So,
Atomic no.= 32
Hence,
The element is Germanium which is a metalloid with 4 valence electrons and has 32 protons in nucleus of each atom because it has atomic no. 32
HOPE IT IS USEFUL