Answer:
7.43 × 10²⁴ m⁻³
Explanation:
Data provided in the question:
Conductivity of a semiconductor specimen, σ = 2.8 × 10⁴ (Ω-m)⁻¹
Electron concentration, n = 2.9 × 10²² m⁻³
Electron mobility,
= 0.14 m²/V-s
Hole mobility,
= 0.023 m²/V-s
Now,
σ = 
or
σ = 
here,
q is the charge on electron = 1.6 × 10⁻¹⁹ C
p is the hole density
thus,
2.8 × 10⁴ = 1.6 × 10⁻¹⁹( 2.9 × 10²² × 0.14 + p × 0.023 )
or
1.75 × 10²³ = 0.406 × 10²² + 0.023p
or
17.094 × 10²² = 0.023p
or
p = 743.217 × 10²²
or
p = 7.43 × 10²⁴ m⁻³
Answer:
A. the charge on their ions
Explanation:
Elements are grouped into the same group in the periodic table if they have the same valence electrons. However, the number of valence electrons an element has, determines the number of charges it can possess.
According to this question, two elements in the same group of the periodic table will have the same charge on their ions because they both have the same number of valence electrons.

1 mole of nitric acid produce 1 mole of ammonium nitrate.
moles in 5000 kg of ammonium nitrate :
( molecular mass of ammonium nitrate is 80 gm/mol )
So, number of moles of nitric acid required are also 62500 moles.
Mass of 62500 moles of nitric acid :

Hence, this is the required solution.
<u>Answer:</u>
is an acid,
is a base,
is conjugate base and
is conjugate acid
<u>Explanation:</u>
According to Bronsted and Lowry's theory:
An acid is defined as a proton donor while a base is defined as a proton acceptor.
In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.
For the given chemical reaction:

is losing a proton thus it is an acid to form
which is its conjugate base
is gaining a proton thus it is a base to form
which is its conjugate acid
Hence,
is an acid,
is a base,
is conjugate base and
is conjugate acid