Explanation:
1. c
2. b
3. b
4. d
5. c
6. b
7.c
8. c
9. d
10. c
11.Liquid water changes to water vapor when it evaporates or boils. The gas inside the bubbles of boiling water is water vapor. Water vapor can change back into liquid water when it cools down. ... The “steam” you see is really tiny drops of liquid water that form when the water vapor cools.
12.Plastic pollution has become one of the most pressing environmental issues, as rapidly increasing production of disposable plastic products overwhelms the world’s ability to deal with them. Plastic pollution is most visible in developing Asian and African nations, where garbage collection systems are often inefficient or nonexistent. But the developed world, especially in countries with low recycling rates, also has trouble properly collecting discarded plastics. Plastic trash has become so ubiquitous it has prompted efforts to write a global treaty negotiated by the United Nations
Each nitrogen molecule had 2 Nitrogen atoms.
So 2 moles of nitrogen gas molecules will have 4 moles of nitrogen atoms.Answer is 2moles
Answer:
The element is Na
Explanation:
Ionization energy is the energy needed to release the last electron from an atom in its ground state to the gaseous state. It is a periodic property that increases as we go through the periods of the periodic table, but decreases if we move in groups. Sodium has thr ionic radius (another periodic property) that is too large, making it easier to release the electron away, since it is too far from the nucleus.
Answer:
Yes
Explanation:
The possibility of evaporating and condensing is a proof of reversible reaction
Answer: 
Explanation:
First we have to calculate the heat absorbed by bomb calorimeter
Formula used :
= heat absorbed by calorimeter = ?
= specific heat of = 10.69 kJ/K
= final temperature = 
= initial temperature = 
As heat absorbed by calorimeter is equal to the heat released by acetylene during combustion.
Thus 1.53 gram of acetylene releases heat of combustion = 258.7kJ
So, 26.04 g/mole of acetylene releases heat of combustion 
Therefore, the heat of combustion of acetylene is,
