Answer:
Bonds are broken and new bonds are formed during chemical reactions only.
Explanation:
- A physical change in a substance doesn't change what the substance is.
- In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
- Physical changes can be reversed, chemical changes cannot be reversed with the substance changed back without extraordinary means, if at all. For example, a cup of water can be frozen when cooled and then can be returned to a liquid form when heated.
So, the right choice is:
Bonds are broken and new bonds are formed during chemical reactions only.
Answer:
0.91 atm is the partial pressure of just hydrogen gas.
Explanation:
Vapor pressure of water , p= 0.0313 atm
Partial pressure of hydrogen gas = 
Total pressure of the water vapors and hydrogen gas = P = 715 Torr
1 atm = 715 Torr

According Dalton's law of partial pressure:



0.91 atm is the partial pressure of just hydrogen gas.
Answer:
9,000, 100 has 7 significant figures
Explanation:
Answer: 0.3794 moles of Iodine gas are produced.
Explanation:

Volume of iodine gas produced at STP =8.5 L
At STP, the 1 mol of gas occupies volume = 22.4 L
So, 8.5 L of volume will be occupied by:
0.3794 moles of Iodine gas are produced.
Like all cells without a nucleus it will not carry DNA thus the inability to reproduce its life span will be short