Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%
Answer:
the action or power of focusing one's attention or mental effort.
Explanation:
Keyword: <em>Focus </em>
The answer to this question would be: 11.5 grams
The molecular mass of hydrogen is 1, oxygen is 16 and carbon is 12. Then the molecular mass of CH4O would be: 12 + 4(1) + 16= 32.
To find the hydrogen mass, you just need to divide the hydrogen with total mass, resulting in the mass ratio of hydrogen to the compound. Then the amount of hydrogen inside 92 gram of CH4O are: 92grams * (4/32)= 11.5 grams
Answer:
B) The molecular orbital formed is lower in energy than a hydrogen 1s atomic orbital.
Explanation:
When two atoms of hydrogen come close to each other , there is formation of molecular orbital . Due to overlap of 1 s orbital of one and 1 s orbital of another atom , two molecular orbitals are formed . One of these molecular orbital has energy less than 1 s atomic orbital . It is called 1 s sigma bonding molecular orbital . The other molecular orbital has energy more than 1 s atomic orbital . It is called antibonding molecular orbital . Two electrons occupy bonding sigma molecular orbital .
So , the statement that "the molecular orbital formed is lower in energy than a hydrogen 1s atomic orbital " is wrong .