which phrase best describes a scientist? a. a person who is highly educated b. a person who learns about the world by observing it. c. a person who understands how the world behaves. d. a person who is extremely knowledgeable about the world

Read the given expression. x = number of protons − number of core electrons which of the following explains the identity of x and its trends across a period? x is the effective nuclear charge, and it remains constant across a period. x is the screening constant, and it remains constant across a period. x is the effective nuclear charge, and it increases across a period. x is the screening constant, and it increases across a period.

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

What is the formula for the compound dinitrogen pentoxide? a. n4o5 b. n5o4 c. n4o6 d. n5o2 e. n2o5