a. They are both normally found as gases in the atmosphere. TRUE
That is correct, the oxygen and nitrogen are found in large quantities in the air around us.
b. They can be either liquids or gases. TRUE
Under certain temperatures any gas will transform into a liquid.
c.They turn from gas to liquid at the same temperature. FALSE
Oxygen it will pass into a liquid at -183 °C while nitrogen pass into a liquid at -195.8 °C.
d.They can be changed from gases to liquids by heating them. FALSE
The gases change to liquids by cooling them.
I believe the correct answer would be that it feels slippery. Being slippery or soapy is one characteristic of a base. This due to the fact that it dissolves the oils and fatty acids from the skin. Other characteristics would be that it turns litmus paper blue and has a bitter taste.
Barium :

with +2 being the charge
Oxygen :

with -2 being the charge
The given equation can be written as:
Ba + O = BaO
Since the sum charges of Barium and Oxygen equals 0, there is no need to add subscripts.
Both Ba and O appear on the left and right side of the equation once, so there is no need to add a coefficient.
Ba + O = BaO is balanced
Answer:
14.3mL you require to reach the half-equivalence point
Explanation:
A strong acid as HClO₄ reacts with a weak base as CH₃CH₂NH₂, thus:
CH₃CH₂NH₂ + HClO₄ → CH₃CH₂NH₃⁺ + ClO₄⁻
As the reaction is 1:1, to reach the equivalence point you require to add the moles of HClO₄ equal to moles CH₃CH₂NH₂ you add originally. Also, half-equivalence point requires to add half-moles of CH₃CH₂NH₂ you add originally.
Initial moles of CH₃CH₂NH₂ are:
20.8mL = 0.0208L × (0.51mol CH₃CH₂NH₂ / 1L) =
0.0106moles CH₃CH₂NH₂
To reach the half-equivalence point you require:
0.0106moles ÷ 2 = 0.005304 moles HClO₄
As concentration of HClO₄ is 0.37M, volume you require to add 0.005304moles is:
0.005304 moles HClO₄ ₓ (1L / 0.37mol) = 0.0143L =
<h3> 14.3mL you require to reach the half-equivalence point</h3>
<h2>Answer : Electromagnetic energy</h2><h3>Explanation :</h3>
The solar panel usually combines multiple photo voltaic cells. Electromagnetic energy is used to power a solar panel. As the electromagnetic energy or rather radiations from the sun reaches to Earth in the form of radiation which is then collected by these photo voltaic cells. As the term solar energy simply suggests that the energy is coming from the sun. Thus, electromagnetic energy coming from the sun was produced when electric charges inside the sun change their potential energy.