Which of the following pairs of elements are chemically most similar to each other?

A. K and Ca
B. C and Si
C. N and O
D. Sn and As

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?

Which factor is likely to impact the possible number of compounds ?