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lora16 [44]
2 years ago
9

If you examined the human body on a chemical composition basis, which of the following combinations of elements would be most co

mmon?
A) O, C, N, Na
B) C, H, Ca, Cl
C) O, C, H, N
D) C, N, Ca, S
E) O, C, P, S
Chemistry
1 answer:
atroni [7]2 years ago
3 0

Answer:

C) O, C, H, N

Explanation:

Roughly 96% of the mass of the human body is made up of the four elements which are carbon, oxygen, hydrogen and nitrogen.

The elements, oxygen and hydrogen are found predominantly in water, which makes up 60% of body's weight approximately. Element carbon is synonymous with life. The central role of the element, carbon is due to the fact that the carbon has 4 bonding sites which allow the element for the building of long and the complex chains of molecules. Nitrogen is found in the organic molecules, including the amino acids which make up proteins, and nucleic acids which make up DNA.

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Why is it important for scientists to use a classification
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So they can tell what exact species it is. 
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Draw a schematic of the hydrogen atom with the single proton in the nucleus, and the n=1, n=2, n=3, and n=4 energy level options
max2010maxim [7]

Explanation:

According to Bohr's postulates, the electron in the present in the lower energy level can absorb energy and exits to higher energy level. Also, when this electron returns back to its orbit, it emits some energy.

Since the hydrogen consists of 1 electron and 1 proton. The lowest energy configuration of the hydrogen is when n =1 or, when the electron is present in the K-shell or the ground state.

The possible transition for the electron given in the question is :

n = 2, 3 and 4

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3 0
3 years ago
2Fe(s) +3H2SO4(aq) →Fe2(SO4)3(aq) +3H2(g)When 10.3 g of iron are reacted with 14.8 moles of sulfuric acid, what is the percent y
Elden [556K]

Answer:

1040%

Explanation:

To solve this question we must convert the mass of Iron to moles in order to find limiting reactant. With limiting reactant we can find the theoretical moles of hydrogen and theoretical mass:

Percent yield = Actual yield (5.40g) / Theoretical yield * 100

<em>Moles Fe -Molar mass: 55.845g/mol-:</em>

10.3g * (1mol / 55.845g) = 0.184 moles of Fe will react.

For a complete reaction of these moles there are necessaries:

0.184 moles Fe* ( 3 mol H2SO4 / 2 mol Fe) = 0.277 moles H2SO4.

As there are 14.8 moles of the acid, <em>Fe is limiting reasctant.</em>

The moles of H2 produced are:

0.184 moles Fe* ( 3 mol H2 / 2 mol Fe) = 0.277 moles H2

The mass is:

0.277 moles H2 * (2.016g/mol) = 0.558g H2

Percent yield is:

5.40g / 0.558g * 100 = 1040%

It is possible the experiment wasn't performed correctly

7 0
2 years ago
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