Fill in the blank.
elements in a family have the same
a. level of reactivity
b. protons and neutrons
c. number of valence electrons

Number of valence electrons

Explanation:

A family of elements is defined as a specific group of those elements. Groups in the periodic table are identified by columns, e. g., group 1A contains alkali metals, group 2A contains alkaline earth metals, group 7A consists of halogens, group 8A contains noble gases etc.

The group number corresponds to the valence electrons these atoms have. The number of protons for each atom is different and the level of reactivity depends on the size of the atom mainly, as well as electronegativity.

C the same number of valence electron

Explanation:

precipitation

explanation:

when it goes from cloud to rain/back to earth in the form of rain

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: