Answer:
A. a magnet
Explanation:
Iron fillings could be separated from sand using a magnet
Answer:

Explanation:
Given that:-
Pressure = 
The expression for the conversion of pressure in Pascal to pressure in atm is shown below:
P (Pa) =
P (atm)
Given the value of pressure = 43,836 Pa
So,
=
atm
Pressure = 6.80977 atm
Volume =
= 2.3 L ( 1 m³ = 1000 L)
n = 2 mol
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the equation as:
6.80977 atm × 2.3 L = 2 mol × 0.0821 L.atm/K.mol × T
⇒T = 95.39 K
The expression for the kinetic energy is:-

k is Boltzmann's constant =
T is the temperature
So, 

I believe the answer would be Neutrons
PH = −log [H+] = − log [5.4 × 10−3] ≈ 2.27 or 2.3.
or basically 2