Understanding Biology

Kenneth A. Mason, Tod Duncan, George B. Johnson

Chapter 2 The Nature of Molecules and the Properties of Water - all with Video Answers

Educators

Section 1

All Matter Is Composed of Atoms

01:14

Problem 1

The isotopes carbon-12 and carbon-14 differ in
a. the number of neutrons.
b. the number of protons.
c. the number of electrons.
d. Both $\mathrm{b}$ and $\mathrm{c}$

Joanna Quigley

Numerade Educator

02:30

Problem 2

An atom with a net positive charge must have more
a. protons than neutrons.
b. protons than electrons.
c. electrons than neutrons.
d. electrons than protons.

Christina Sorrentino

Numerade Educator

01:06

Problem 3

A completely filled L energy level contains how many more electrons than a completely filled $\mathrm{K}$ energy level?
a. two
b. four
c. $\mathrm{six}$
d. eight

Joanna Quigley

Numerade Educator

01:15

Problem 4

$\mathrm{Ca}^{2+}$
a. is an anion.
b. is a neutral isotope.
c. is an atom that has lost two electrons.
d. is reduced.

Joanna Quigley

Numerade Educator