Answer:
1.242 g/mL
Explanation:
Step 1: Given data
Mass of the empty container (m₁): 80.21 g
Mass of the filled container (m₂): 105.22 g
Volume of the unknown liquid (V): 20.14 mL
Step 2: Calculate the mass of the liquid
The mass of the liquid is equal to the difference between the mass of the filled container and the mass of the empty container.

Step 3: Calculate the density of the unknown liquid
The density of the liquid is equal to its mass divided by its volume.

Answer:
The symbol of the ion is A^-
Explanation:
Let A be the symbol of the element.
Proton = 17
Electron = 18
Neutron = 20
Since the element has more electrons than protons, it means it has gain electrons.
From the question given,
The difference between the electron and proton = 18 — 17 = 1
So, the element has gain 1 electron.
Therefore the symbol of the ion is A^-
1.4mL
Explanation:
Given parameters:
Mass of object = 3.5g
density = 2.5g/mL
Unknown:
Volume of the object = ?
Solution:
Density is the mass per unit volume of a body. It is an intensive property that is the same for the same substances.
Density = 
since the volume is unknown; we make it the subject of the formula;
Volume = 
Volume = 
Volume of the object = 1.4mL
learn more:
Density brainly.com/question/4825250
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C.
The energy produced by the Sun comes from nuclear fusion reactions.
Explanation
during formation of the solar system the centrifugal force of the sun caused it to collapse on it's self initialising nuclear fusion.
Ultraviolet light has higher frequency and higher radiant energy.
Look up a chart on electromagnetic radiation if you need further help.