Density = mass / volume
D = 550 / 25
D = 22 g/mL
hope this helps!
A for the first and b for the second!!:))
Answer:

Explanation:
Mass ( m ) = 52 kg
Acceleration ( a ) = 5 m / s²
Force ( F ) = ?
According to Newton's second law of motion ,



Hope I helped!
Best regards! :D
Answer:
will form a precipitate of insoluble
when aqueous
is added.
Explanation:
According to solubility rule-
all carbonates are insoluble except group IA compounds and 
all salts of sodium are soluble
When
is added to given solutions, a double displacement reaction takes place in each solution to form a sodium salt and a carbonate salt.
So, in accordance with solubility rule, addition of
into
will result precipitation of insoluble 
Reaction: 
A lone pair is a pair of valence electrons that are not shared with another atom and is sometimes called a non-bonding pair.