Question

multiple choice 10 points
which statement describes the structure of a water molecule?
it is composed of two hydrogen atoms covalently bonded to a central oxygen atom.
it is composed of two oxygen atoms ionically bonded to a central hydrogen atom.
it is composed of one hydrogen atom metallically bonded to a central oxygen atom.
it is composed of two oxygen atoms covalently bonded to a central hydrogen atom.
8 multiple choice 10 points
what causes the two hydrogen atoms in a water molecule to be positioned at an angle?
the hydrogen atoms are attracted to each other, causing them to bend together.
the oxygen atom repels the hydrogen atoms due to its lone pairs of electrons.
the tetrahedral structure around oxygen forces the hydrogen atoms to form an angle.
the hydrogen atoms are too large to be positioned directly opposite each other.

Explanation:

For the first question, the chemical formula of water is $H_2O$, where two hydrogen atoms are covalently bonded to a central oxygen atom. For the second question, the oxygen atom in water has two bonding - pairs and two lone - pairs of electrons. According to the valence - shell electron - pair repulsion (VSEPR) theory, the electron - pairs around the oxygen atom arrange themselves in a tetrahedral geometry, which forces the two hydrogen atoms to form an angle.

Answer:

1. It is composed of two hydrogen atoms covalently bonded to a central oxygen atom.
2. The tetrahedral structure around oxygen forces the hydrogen atoms to form an angle.