The correct option is FLUORINE AND COPPER.
An ionic compound is usually formed by the combination of a metal and a non metal, the metal usually act as an electron donor while the non metal act as an electron acceptor. Thus, in ionic compounds, there is total transfer of electrons from the metal to the non metal. In the question given here, copper is the metal while the fluorine is the non metal.<span />
Within the core of the Sun, temperatures and pressures are high enough to fuse hydrogen atoms into helium, which is the Sun's main form of energy production. Assuming there was a slight mistake in where you have copied the results here the correct answer is the third option.
Hope this helps!
The reaction between hydrogen and oxygen to form water is given as:

The balanced reaction is:

According to the balanced reaction,
4 g of hydrogen (
) reacts with 32 g of oxygen (
).
So, oxygen reacted with 29.4 g of hydrogen is:

Hence, the mass of oxygen that is reacted with 29.4 g of hydrogen is 235.2 g.
Answer:
b) coefficient
Explanation:
Refer to this example:
CH4 +2 O2 → CO2+ 2 H2O
2 is used as a coefficient in this chemical equation.
Answer:
Distance
Explanation:
The light-year is a measure of distance, not time. It is the total distance that a beam of light, moving in a straight line, travels in one year.