Oxygen is 21% and nitrogen is 78% so combined is 99%
Answer:

Explanation:
Hello,
In this case, since the Lewis theory is based on the bonds formation between atoms via the valence electrons, we can verify the chemical formula of the compound formed by strontium and nitrogen by noticing that strontium has two valence electrons as it is in group IIA, for that reason, two nitrogens should be available for bonding. Therefore, since nitrogen is in group VA, it is said that three electrons are required to attain the octet (maximum amount bonded electrons), for that reason, three strontiums are should be available for bonding. In such a way, the formula should be:

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Answer:
I think the answer would be A.
In general chemistry, isomers are two or more elements that have the same number of protons but differ in mass number. In organic chemistry, the compounds are cis or trans isomers if they have the same chemical formula, but differ in the placement of functional groups based on molecular geometry. Cis isomer is when two like functional groups are on the same side of the molecules, while trans isomer is when the like functional groups are on opposite sides.
The cis-trans isomers are shown in the picture. As you can see, in the cis isomer, the methane functional group are both in the same side. Same as well with the hydrogen atoms. On the other hand, these functional groups are opposite to each other in the trans isomer.
The height of the described cylinder is 0.85 cm
Mass= 98g
Density= 8.9g/cm^3
Density= (mass/volume)
Substitute the values
8.94= 98/ volume
Volume= 
Volume= 10.97
Volume of a cylinder can be found with (V = π r 2 h.)
h= height of cylinder ?
radius= 2cm
Substitute the values
10.97= π ×
× h
h= 10.97/12.57
h= 0.85 cm
Therefore, height of the described cylinder is 0.85 cm
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