Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density. Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density.
From: www.middleschoolchemistry.com
Answer:
1 True
2. True
3. True
4. True
5. False
Explanation:
1. Hypochlorous acid (HOCl) is a weak acid that forms when chlorine dissolves in water, and is partially dissociated, forming hypochlorite. HOCl is considered a strong oxidizing agent responsible for the killing action of germs in chlorine solutions.
2. Acetic acid is also known as ethanoic acid. It has a distinctive sour taste and pungent smell, and is generally considered a weak acid. in a concentrated form, acetic acid can be corrosive.
3/4 . Methylene chloride is an organochloride compound with the formula CH2Cl2. It is a colorless, volatile liquid with a moderately sweet aroma is widely used as a solvent. It is normally stable, non-flammable and non-explosive when mixed with air at temperatures below 100 °C, but its vapor is flammable only when present in relatively high concentrations of about 14% to 22% in air. Research shows that it is very much possibly carcinogenic, and it has been linked to cancer of the lungs, liver, pancreas, breast cancer and salivary gland cancer in laboratory animals.
5. Laboratory and medical waste are not to be disposed in the trash with regular wastes, as they are potentially toxic. Special disposal methods and agencies exists to take away such wastes.
Answer:
B) The term "inert" was dropped because it no longer described all the group 8A elements.
Explanation:
Inert elements in chemistry simply refers to elements that are chemically inactive and are not expected to form any compounds. this is the general belief for the group 8 elements as they all have complete duplet/octet configurations (and ideally, they ought to be very stable with no tendency to form compounds by participating in the loss and gain of electrons). However the discovery of compounds like xenon tetrafluoride (XeF4) proved this to be wrong.
Again, the reason the term - inert gses was droppedis beacause this term is not strictly accurate because several of them do take part in chemical reactions.
After dropping the term - Inert gases, they are now referred to as noble gases.
The two types of energy changes that occur are heat and light changes.
