The chemical reaction that joins glucose and fructose to form sucrose is called ___.

Refer to the DNA double helix. The sugars and phosphates are joined by [a] bonds (arrow tips). The two polynucleotide strands are held together by [b] bonds. (enclosed by box) The base [c] pairs with adenine A. The sugar in the backbone of DNA is [d].    

The chemical equation shows [a]. The product OH- is called [b].

Refer to the structural formula of the molecule alanine. The line joining two atoms represents a [a] bond. Except for H, all atoms of alanine are stable because they have [b] valence electrons. Which bond in alanine is nonpolar? [c] Which atom in alanine is the most electronegative? [d] Which atom in alanine can be partially positive? [e]

Which subatomic particle has a negative charge?

A hydrogen bond is ___ a covalent bond.

The figure shows the structure of an electrically neutral nitrogen atom. The circles on the shells are [a]. Nitrogen has [b] valence electrons. Nitrogen will form [c] covalent bonds.

These two glucose molecules are ___.

Isotopes 31P and 32P differ in the number of ___.

Atoms of an element have the same number of ___.