Chapter 1
A scientist is working in the lab, with compounds containing carbon. She is most likely working in the field of
organic chemistry.
In an experiment, onion plants of different ages were exposed to various amounts of caffeine to determine the effect of caffeine on cell growth. Temperature, amount of water, and light were kept constant. Which of these statements about the experiment is definitely true?
The results may not be valid because there were two variables.
Neutral atoms contain equal numbers of
protons and electrons.
The diagram (up arrow, down arrow) represents two electrons with
opposite spin states.
Mendeleev organized the chemical elements based on their
properties.
The branch of chemistry called analytical chemistry most likely would be used in determining the
chemical composition of a new substance.
What is the variable in an experiment designed to determine whether steel rusts more quickly near a lake or in a desert in one year?
amount of water in the air
The atomic mass of an atom of carbon is 12 amu, and the atomic mass of an atom of oxygen is 16 amu. To produce CO, 16 g of oxygen combine with 12 g of carbon. To produce CO2, 32 g of oxygen combine with 12g of carbon. The ratio of the mass of oxygen in CO2 to the mass of oxygen in CO is
2:1
3. Which of the following quantum numbers describes a p-orbital in the third energy level?
a. n = 3, l = 0, m = 0
b. n = 3, l = 1, m = 0
c. n = 3, l = −1, m = 0
d. n = 4, l = 1, m = 0
b. n = 3, l = 1, m = 0
The periodic law states that
the physical and chemical properties of the elements are functions of their atomic number.
A scientist is working with mathematical and computer models to learn about the principles at work in a chemical reaction. He is working in the field of
theoretical chemistry.
Which of these terms best describes the following statement? “A solution of the unknown compound turned litmus paper blue.”
qualitative observation
5. Which of the following is not one of the five principles of Dalton’s theory?
a. Atoms of different elements combine in simple, whole-number ratios to form compounds.
b. All matter is made of indivisible, indestructible atoms.
c. All atoms have similar physical and chemical properties.
d. Chemical reactions consist of the combination, separation, or rearrangement of atoms.
c. All atoms have similar physical and chemical properties.
The electron configuration on your study guide violates what?
c. Hund’s rule.
An element with the general electron configuration ns2np1 for its outermost electrons would be in Group
13.
A scientist is working to improve a product that uses fiber optics. This is an example of
Both applied research and technological development.
Which of these statements is true of the scientific method?
A. The steps may vary somewhat to suit the experiment.
B. Working scientists rarely use it.
C. Scientists must follow its steps exactly.
D. Scientists rarely publish results of experiments.
a. The steps may vary somewhat to suit the experiment.
According to the law of definite proportions, any two samples of KCl will have
the same elements in the same proportions by mass.
A photon is emitted from a gaseous atom when an electron moves to its ground state from a(n)
b. excited state.
When a carbon atom is in its ground state, how many electrons does it have in its outermost shell?
4
To find a safer chemical for industrial purposes, a scientist is working with chemicals that do not cause depletion of ozone in the atmosphere. This is an example of
applied research.
Theories are considered successful only if they what?
can be used to make accurate predictions.
Thomson’s experiment showed that the charge-to-mass ratio of electrons was
c. the same in all gases.
The lowest energy state of an atom is its
ground state.
Which of the following elements is most similar in behavior to calcium?
a. magnesium
b. sodium
c. sulfur
d. chlorine
a. magnesium