Water is a compound because it is what? water is a compound because it

a. cannot be broken down into simpler substances.

b. always has two hydrogen atoms for each oxygen atom.

c. is made of water atoms joined together.

d. both a and b

Water is a compound because it always has two hydrogen atoms for each oxygen atom. Water can be broken down into simpler substances. Water is a compound because pure water is composed of only H₂O molecules. Each molecule of water is a chemical combination of two hydrogen atoms and one oxygen atom.  Water is a type of molecular compound.

Further explanationCompounds are substances composed of two or more different elements chemically combined that can be separated into simpler substances only by chemical reactions. Water, for example, is a compound because pure water is composed of only H₂O molecules. Each molecule of water is a chemical combination of two hydrogen atoms and one oxygen atom.A molecular bond or covalent bond occurs as a result of electrons can be shared between atoms. Molecular compounds have molecular (covalent) bonds.An ionic bond occurs as a result of electrons can be completely removed from one atom and given to another. Ionic compounds have ionic bonds.Examples of other molecular compounds are carbon dioxide (CO₂) and glucose (C₆H₁₂O₆). Each molecule of CO₂ is a chemical combination of two oxygen atoms and one carbon atom. Each molecule of C₆H₁₂O₆ is a chemical combination of six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.Table salt (NaCl) is a compound because it is made from more than one kind of element (Na and Cl), but it is not a molecule because the bond that holds NaCl together is an ionic bond. An electron from the outer shell of sodium is released and taken by chlorine to reach octet conditions on both sides, that is how ionic bonds occur. Thus NaCl is an ionic compound.A diatomic molecule is a molecule made from two atoms of the same type. For example, oxygen gas in the atmosphere is a molecule because it contains molecular bonds. It is not a compound because it is made from atoms of only one element, i.e. oxygen. Another example is hydrogen gas, nitrogen gas, and chlorine gas.Elements are the simplest forms of matter and therefore cannot be broken down into simpler substances by any chemical or physical reactions. Some examples of elements include hydrogen, oxygen, carbon, sodium, iron, and sulfur. Elements can combine with other elements to synthesize compounds.  Learn moreWhich statement best explains water’s ability to dissolve covalent compounds? linkHow do ionic bonds differ from covalent bonds? linkWhich elements can react to produce a molecular compound? link

Keywords: water, H₂O, molecular compound, because,  can be broken down into, separated, simpler substances,  always has two hydrogen atoms, for each, is made of, joined together, covalent, ionic, chemical reactions, means, composed,  of two or more, different elements, combined

W = 62.5 J

Explanation:

Given that,

Mass of a baseball, m = 0.2 kg

Initial speed of first student, u = 25 m/s

Finally, the ball stops, v = 0

We need to find the work done by the second student in stopping the ball. We know that, work done is equal to the change in kinetic energy. It can be given by :

So, the required work done is 62.5 J.