How do atoms achieve noble-gas electron configurations in single covalent bonds?

two atoms share two pairs of electrons.

two atoms share one electron.

one atom completely loses two electrons to the other atom in the bond.

two atoms share two electrons.

Answer : The correct option is, Two atoms share two electrons.

Explanation:

Ionic bond : It is defined as the bond that is formed by complete transfer of electrons from one atom to another atom.

That means, the atom which looses the electron is known as electropositive atom and the atom which gains the electron is known as electronegative atom.

The ionic bond is usually formed between a metal and a non-metal.

Covalent bond : It is defined as the bond which is formed when sharing of electrons takes place between the atoms.

This is usually formed between two non-metals.

As per question, for making a single covalent bond the two atoms share their two electrons.

Hence, the correct option is, Two atoms share two electrons.

they begin to vibrate harder causing the material that was solid to turn into a liquid i.e gallium or ice

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.