Answer:
(C) O, C, H, N
Explanation:
<u>Roughly 96% of mass of human body is made up of four elements which are oxygen, carbon, nitrogen and hydrogen.</u>
Oxygen and hydrogen are predominantly found in the water, which makes up about 60% of body's weight. Carbon is synonymous with the life. The central role of carbon is due to fact that it has four bonding sites which allow for building of long and complex chains of the molecules. Moreover, these carbon bonds can be formed and also be broken with amount of energy which makes life alive. Nitrogen is found in organic molecules, including amino acids which make up the proteins, and nucleic acids which make up the DNA.
Answer:
MoClBr₂
Explanation:
First we calculate the mass of bromine in the compound:
- 300.00 g - (82.46224 g + 45.741 g) = 171.79676 g
Then we<u> calculate the number of moles of each element</u>, using their <em>respective molar masses</em>:
- 82.46224 g Mo ÷ 95.95 g/mol = 0.9594 mol Mo
- 45.741 g Cl ÷ 35.45 g/mol = 1.290 mol Cl
- 171.79676 g Br ÷79.9 g/mol = 2.150 mol Br
Now we <u>divide those numbers of moles by the lowest number among them</u>:
- 0.9594 mol Mo / 0.9594 = 1
- 1.290 mol Cl / 0.9594 = 1.34 ≅ 1
- 2.150 mol Br / 0.9594 = 2.24 ≅ 2
Meaning the empirical formula is MoClBr₂.
The answer is D. His belief is was that atoms could not be split. That is what was disproved really fast ;)
When equilibrium has been reached so, according to this formula we can get the specific heat of the unknown metal and from it, we can define the metal as each metal has its specific heat:
Mw*Cw*ΔTw = Mm*Cm*ΔTm
when
Mw → mass of water
Cw → specific heat of water
ΔTw → difference in temperature for water
Mm→ mass of metal
Cw→ specific heat of the metal
ΔTm → difference in temperature for metal
by substitution:
100g * 4.18 * (40-39.8) = 8.23 g * Cm * (50-40)
∴ Cm = 83.6 / 82.3 = 1.02 J/g.°C
when the Cm of the Magnesium ∴ the unknown metal is Mg
