Answer : The answer is, 
Explanation :
Scientific notation : It is defined as the way or representation of expressing the number that are too big or too small that is written in the decimal form. That means always written in the power of 10 form.
For example : 8000 is written as, 
in this notation, the significant figure is, 1 but 
in this notation, the significant figures are, 2
The given problem are :
According to the divide and multiplication rules of scientific figures, the final answer is only as precise as the value with the least number of significant figures.
Hence, the answer is,
Some benefits are that DDT helps us grow crops and keeps pests off our crops.
But DDT is harmful to the environment. If it gets into the water ways then if can harm fish and animals that eat the fish such as birds.
The atom<span> then has more protons than electrons and so it will be positively charged, a positive </span>ion<span>. Example: A </span>magnesium atom<span> may lose two electrons and </span>become<span> a Mg2+ </span>ion<span>. Non-metal </span>atoms<span> may gain electrons and </span>become<span> negatively charged. ... (It loses two electrons.)</span>
Answer:
C₂Cl₄
Explanation:
To know if free rotation around a bond in a compound is possible, we need to see the structure of the compound (picture in attachment).
In single bonds, which are formed by σ bonds, the atoms are not fixed in a single position, and free rotation is permitted.
Double and triple bonds are formed by a σ bond and one or two π bonds, respectively. These bonds do not allow rotation, since it is not possible to twist the ends without breaking the π bond.
The chloroethylene (C₂Cl₄) has two carbons with an sp2-sp2 hybridization, they are bonded together by a double bond. <u>Free rotation on this bond is not possible, because six atoms, including the carbon atoms, doubly bonded and the four chlorine atoms bonded to them, must be on the same plane. </u>
