Mass number is the sum of protons and neutrons inside an atom.
Atomic mass = no. of protons + no. of neutrons
Answer: A 59.5 degree celcius
The equation that we will use to solve this problem is :
PV = nRT where:
P is the pressure of gas = 1.8 atm
V is the volume of gas = 18.2 liters
n is the number of moles of gas = 1.2 moles
R is the gas constant = 0.0821
T is the temperature required (calculated in kelvin)
Using these values to substitute in the equation, we find that:
(1.8)(18.2) = (1.2)(0.0821)(T)
T = 332.5 degree kelvin
The last step is to convert the degree kelvin into degree celcius:
T = 332.5 - 273 = 59.5 degree celcius
Light does not travel at a constant speed in a vacuum, compared to in air, because the light is being absorbed by atoms and molecules in the air. But light does travel at a constant speed in a vacuum.
So I agree with A
All that talk about moving forward is irrelevant (I think)
The given question is incomplete. The complete question is :
In each row check off the boxes that apply to the underlined reactant. The underlined reactant acts as a... (check all that apply)
1. 
here underlined is 
A. Brønsted-Lowry acid
B. Brønsted-Lowry base
C. Lewis acid
D. Lewis base
2. 
Here underlined is 
A. Brønsted-Lowry acid
B. Brønsted-Lowry base
C. Lewis acid
D. Lewis base
3. 
Here underlined is 
A. Brønsted-Lowry acid
B. Brønsted-Lowry base
C. Lewis acid
D. Lewis base
Answer: 1. Brønsted-Lowry acid
2. Lewis base
3. Brønsted-Lowry base
Explanation:
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
1. 
As 
is donating a proton , it acts as a bronsted acid.
2.
As contains a lone pair of electron on nitrogen , it can easily donate electrons to 
and act as lewi base.
3.
As 
is accepting a proton , it acts as a bronsted base.
