When you boil water, you aren't changing the elements. You're just making water vapor. However, when you burn paper, it becomes carbon (mostly). So physical changes will not change the substance, only chemical changes will.
Answer:
Many areas of the United States experience explosive population growth. <u>The more people that reside someplace, the more demand there is for water there.</u> Often these urban-growth <u>expansions are unplanned and place extraordinary stress on the water supply system, mainly on the groundwater.</u> <u>The stress often depletes groundwater supply, thereby causing wells to dry up.</u> Then water must be brought from somewhere else to support the local population.
Such situations have occurred all over the United States. For example, increased population growth in the southwestern United States has significantly lowered the water table 50 to 200 feet (depending on the area) since the 1940s. Managing urban growth, efforts to reduce water demand, conservation of the resource, and attempts to increase the water supply all address the problem of exceeding water resource limits.
<u>Human activities affect groundwater quality.</u>
<u>Here are some sources </u>and possible solutions to groundwater pollution:
<u>Agriculture</u>—Reduce usage of pesticides and fertilizers.
<u>Landfills</u>—Monitor for leakage and repair linings.
<u>Underground storage tanks</u>—Remove damaged and unused tanks.
<u>Household wastes</u>—Properly dispose of household hazardous waste.
<u>Septic tank leaks</u>—Properly maintain and repair tanks.
Explanation:
This came from the K12 learning course read this and the answer will be there. I underlined the important parts for the answer.
Answer:
The answer to your question is: letter A
Explanation:
If an atom lose 3 electrons its charge will be positive, it will be +3
Salt: NaCl
Hydrogen gas: H2
