<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We do as follows:
</span>10 mol NH3 ( 6.022 x 10^23 molecules / 1 mol ) = 6.022x10^24 molecules NH3
Answer:
The bottom layers of the rock could have formed before life occurred.
Explanation:
The bottom layers of the rock could have formed before life occurred because there is no fossil is present. If there is life at that time so the fossils are present at the bottom layer so the absence indicates that is no life present at that time. The bottom layer is older than the upper layer so that's why fossils of bacteria are found in the upper layer of the rock.
Answer:
C. Because bacterial fossils are found only in the upper layers, scientists can conclude that these bacteria evolved towards the end of Precambrian time.
There’s two different types of answers for this question so I just put both of them. Hope it helps : )
Answer:
23.8g of sodium phosphate are formed
Explanation:
Based on the reaction of sodium, Na, with phosphoric acid, H₃PO₄:
3Na + H₃PO₄ → Na₃PO₄ + 3/2 H₂
<em>3 moles of sodium produce 1 mole of sodium phosphate</em>
<em />
To solve this question we must find the moles of sodium in 10g. Using the chemical reaction we can find the moles -And the mass- of sodium phosphate produced, as follows:
<em>Moles Na -Molar mass: 22.99g/mol-</em>
10g * (1mol / 22.99g) = 0.435 moles Na
<em>Moles Na₃PO₄:</em>
0.435 moles Na * (1mol Na₃PO₄ / 3mol Na) = 0.145 moles Na₃PO₄
<em>Mass Na₃PO₄ -Molar mass: 163.94g/mol-</em>
0.145 moles Na₃PO₄ * (163.94g/mol) =
<h3>23.8g of sodium phosphate are formed</h3>
Answer:
an estimate of the strength of a bond.
Explanation:
The bond order is given as;
1/2(number of bonding electrons - number of anti bonding electrons)
The bond order tells us about the strength of bond. As the bond order increases, so does the strength of the bond because atoms involved in bonding come closer to each other as the bond length decreases.
Hence, bond order is an index of bond strength. Triple bonds are stronger than double bonds which are stronger than single bonds.
