The correct answer is C : energy level.
As you can see in the image of the periodic table presented below, periods are the horizontal columns of the periodic table.
Elements belonging to the same period have the same electron shell, the same number of orbits filled with electrons.
Elements of the same period have similar chemical and physical characteristics
The answer would be option B "I believe there is life on other planets." Scientific statements have a possibility to be wrong. It's not option A because option A is a opinion. It's not option C because option C is a fact. It's not option D because option D is a opinion.
Hope this helps!
Answer:
The volume of the gas is 2.80 L.
Explanation:
An ideal gas is a theoretical gas that is considered to be made up of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The Pressure (P) of a gas on the walls of the container that contains it, the Volume (V) it occupies, the Temperature (T) at which it is located and the amount of substance it contains (number of moles, n) are related from the equation known as Equation of State of Ideal Gases:
P*V = n*R*T
where R is the constant of ideal gases.
In this case:
- P= 2 atm
- V= ?
- n=0.223 moles
- R= 0.0821

- T=33 °C= 306 °K (being O°C= 273°K)
Replacing:
2 atm* V= 0.223 moles*0.0821
* 306 K
Solving:

V= 2.80 L
<u><em>The volume of the gas is 2.80 L.</em></u>
Answer:
the catalyst is the two gray dots
Sodium, hydrogen, carbon, and oxygen