Answer:
D. 9.
Step-by-step explanation:
One formula unit of NaOH contains <em>three atoms</em>: 1 Na, 1 O, and 1 H.
3 formula units × (3 atoms/1 formula unit) = 9 atoms
Answer:
"Like dissolves like" is an expression used by chemists to remember how some solvents work. It refers to "polar" and "nonpolar" solvents and solutes. Like dissolves like, that means polar dissolves polar, so water dissolves salt.
Explanation:
B) The light source can be seen from the penumbra.