Answer:
The correct option is: stable environment
Explanation:
According to the Darwin's theory, natural selection is the concept by which all the small useful variations of traits are preserved.
According to Darwin, there are three <u>necessary and sufficient conditions</u> for the occurrence of natural selection:
1. struggle for existence
2. variation
3. inheritance
These conditions are said to be necessary because if these conditions are not satisfied then natural selection does not occur.
These conditions are said to be sufficient because if these conditions are satisfied, then natural selection will most definitely occur.
Answer:
20.53 g.
Explanation:
- Knowing that every 15.0 g of pure calcium fluoride contains 7.70 g of calcium.
<u>Using cross multiplication:</u>
15.0 g of pure calcium fluoride contains → 7.70 g of calcium.
40.0 g of pure calcium fluoride contains → ??? g of calcium.
<em>∴ The mass of Ca in 40.0 g of calcium fluoride</em> = (7.70 g)(40.0 g)/(15.0 g) = <em>20.53 g.</em>
It's not B so I'm thinking it is D.
Answer:
See explaination andd attachment
Explanation:
Treatment of aldehydes and ketones with a suitable base can lead to the formation of a nucleophilic species called an enolate that reacts with electrophiles. These C nucleophiles are useful for making new carbon-carbon bonds.
Please kindly see attachment for the drawings.