Which of the following contains covalent bonds?ABrassBMagnesium chlorideCWaterDSodium chloride

The answer is C. Water.

Here's why:

A covalent bond is a type of chemical bond where two atoms are connected to each other by the sharing of two or more electrons.

A. Brass is an alloy made primarily of copper and zinc, not a covalent compound.

B. Magnesium chloride (MgCl2) is an ionic compound. In this compound, magnesium has a +2 charge and chloride has a -1 charge. They transfer electrons to achieve stability, not share them.

C. Water (H2O) is a covalent compound. The oxygen atom shares one electron with each hydrogen atom.

D. Sodium chloride (NaCl) is also an ionic compound. Sodium (Na) has a +1 charge and chloride (Cl) has a -1 charge. They transfer electrons to achieve stability, not share them.