Answer:
Math expression: 
Explanation:
<u>Given:</u>
Energy produced per gram of gasoline = 45.0 kJ
Density of gasoline = 0.77 g/ml
Volume of gasoline = 5.2 L=5200 ml
<u>To determine:</u>
The amount of energy produced by burning 5.2 L gasoline
<u>Calculation set-up:</u>
1. Calculate the mass (m) of gasoline given the density (d) and volume (v)

2. Calculate the amount of energy produced

Answer:
Scientists consider human to be" carbon creatures" because carbon atoms form the backbone or foundation of pretty much the essential biological molecules floating around in our bodies (except water, of course.) All in all, scientists can consider humans to be " carbon creatures" because our skin, hair and cells are all made out of molecules that contain huge amounts of carbon.
Hope this helps! God bless!
Answer: Option (d) is the correct answer.
Explanation:
At high temperature, there will be more collision between the molecules as a result more energy will generate. Thus, a wave can move quickly.
In case of solids, the particles are held more closely with each other. Therefore, when temperature is high then solid particles being closer can pass on the energy more quickly as compared to gases.
Thus, we can conclude that waves move fastest in high-temperature solids.
Answer : The hydroxide ion concentration of a solution is, 
Explanation :
As we know that:
pH : It is defined as the negative logarithm of hydrogen ion concentration.
Mathematically,
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Similarly,
pOH : It is defined as the negative logarithm of hydroxide ion concentration.
Mathematically,
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
Given:
pOH = 6.42
![6.42=-\log [OH^-]](https://tex.z-dn.net/?f=6.42%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=3.8\times 10^{-7}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D3.8%5Ctimes%2010%5E%7B-7%7DM)
Therefore, the hydroxide ion concentration of a solution is, 
It is commonly known that our Galaxy rotates upon the sun because of gravity. The diagrams' arrows sort of describe it. Id suggest Gravity as the answer.