Internal means inside and external means outside
Answer:
6.9 hours
Explanation:
In order to solve this problem we'll<u> convert 837 km to miles</u> (another option would be to convert 75 mi/hr to km/hr). To make said conversion we'll use the given <em>conversion factor</em>:
- 837 km * = 519.88 mi
Finally we <u>calculate the time required to travel said distance</u> at a constant speed of 75 mi/hr:
- 519.88 mi ÷ 75 mi/hr = 6.9 hr
Answer:
Hydrogen
Explanation:
Hydrogen has only 1 proton and has an atomic mass of 1. It does not have neutrons. Helium and above have higher mass than Hydrogen.
Answer:
When bonds are formed energy is released.
When bonds are broken energy is required or absorbed.
Explanation:
The energy changes occur during the bonds formation and bonds breaking.
There ere two types of reaction endothermic and exothermic reaction.
Endothermic reactions:
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
Exothermic reaction:
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol