﻿(1) What is the definition of a scientific theory? (1 points)
A) a brief statement that summarizes past observations and predicts future ones
B) a model that explains the underlying reasons for observations and laws
C) the equivalent of a scientific opinion which others may disagree with
D) a method of learning that emphasizes reason as the way to understand the world
E) none of the above

(2) The definition of a scientific law is:     (1 point)
A) the same as a hypothesis.
B) a way of learning that emphasizes observation and experimentation.	
C) the underlying reason for a scientific theory.
D) a number of similar observations generalized into a brief statement summarizing past observations and predicting new ones.
E) none of the above

(3) The distance between the two hydrogen atoms in a molecule of water is 0.000000000172 m. Express this distance in scientific notation.    (1 point)
A) 1.72 ×10-9 m
B) 1.72 × 10-10 m
C) 0.172 × 10-10 m
D) 17.2 × 109 m
E) 1.72 × 1010 m

(4) In the number 48.93, which digit is estimated?    (1 point)
A) 4
B) 8
C) 9
D) 3

(5) The correct number of significant figures in the number 1.250100 is:    (1 point)
A) 5
B) 7
C) 4
D) ambiguous
E) none of the above

(6) Determine the answer to the following equation with correct number of significant figures:    (1 point)
13.96 - 4.9102 + 71.5 = ________ 
A) 80.5498
B) 81
C) 80.5
D) 80.55
E) none of the above

(7) How many significant figures should be reported in the answer to the following calculation?    (1 point) 
(8.50) × (29.0) × (1.0947) =    
A) 3
B) 2
C) 4
D) 5
E) none of the above

(8) Which of the following is NOT an example of matter?    (1 point)
A) a pencil eraser
B) a balloon full of helium
C) a dust particle
D) heat from a burning candle
E) none of the above

(9) Which state of matter has atomic spacing that is close together and indefinite shape?    (1 point)
A) liquid
B) solid
C) gas
D) plasma
E) none of the above

(10) How would you classify salt water?    (1 point)
A) pure substance-compound
B) mixture-heterogeneous
C) pure substance-element
D) mixture-homogeneous
E) none of the above

(11) Which of the following statements about physical and chemical changes is FALSE?    (1 point)
A) In a chemical change, matter changes its composition.
B) In a physical change, matter does not change its composition.
C) Phase changes are always physical changes.
D) Chemical reactions are chemical changes.
E) All of the above statements are true.

(12) Which type of energy is associated with motion?    (1 point)
A) chemical
B) electrical
C) potential
D) kinetic
E) none of the above

(13) Which of the following items is NOT a common unit of energy?    (1 point)
A) joule
B) torr
C) calorie
D) kilowatt-hour
E) none of the above

(14) The boiling point of water is    (1 point)
	(1)	212 °F	(2)	0°C	(3)	373 K
A) 1 and 2 only
B) 2 and 3 only
C) 1 and 3 only
D) all of 1, 2, and 3
E) none of 1, 2, and 3

(15) How many Calories are in 575.0 calories?    (1 point)
A) 575,000
B) 0.5750
C) 137.6
D) 2,404
E) none of the above

(16) Metals are located where on the periodic table?    (1 point)
A) left side
B) right side
C) middle
D) zig-zag diagonal line
E) none of the above

(17) Nonmetals are located where on the periodic table?    (1 point)
A) left side
B) right side
C) middle
D) zig-zag diagonal line
E) none of the above

(18) When an atom loses an electron, the resulting particle is called    (1 point)
A) a proton.
B) an anion.
C) a cation.
D) an isotope.
E) none of the above

(19) When an atom gains an electron, the resulting particle is called    (1 point)
A) a proton.
B) an anion.
C) a cation.
D) an isotope.
E) none of the above

(20) What is the charge on the ion formed by aluminum?    (1 point)
A) 5-
B) 3-
C) 13+
D) 3+
E) none of the above

(21) What is the charge on the cesium (caesium) ion?    (1 point)
A) 1-
B) 2-
C) 1+
D) 2+
E) none of the above

(22) How many neutrons are present in Ne-22?    (1 point)
A) 12
B) 10
C) 22
D) 32
E) none of the above

(23) When elements combine to form compounds,     (1 point)
A) their properties are an average of all elements in the compound.
B) their properties change completely.
C) their properties do not change.
D) they always turn purple
E) none of the above

(24) The law of constant composition states:    (1 point)
A) Matter cannot be either created or destroyed in a chemical reaction.
B) The nucleus is a dense region of positive charge that always contains protons and neutrons.
C) All samples of a given compound have the same proportions of their constituent elements.
D) All atoms of a given element have a constant composition and are different than atoms of any other element.
E) none of the above

(25) Which of the following statements about chemical formulas is FALSE?    (1 point)
A) The subscripts represent the relative number of each type of atom in the compound.	
B) The subscripts represent the relative mass of each type of atom in the compound.
C) The subscripts do not change for a given compound.	
D) Different compounds made of the same elements have different subscripts.
E) All of the statements are true.

(26) How many total atoms are in the formula Al2(CO3)3?     (1 point)
A) 8
B) 9
C) 12
D) 14
E) none of the above

(27) How many of each type of atom are there in the formula (NH4)2HPO4?    (1 point)
A) N = 2, H = 9, P = 1, O = 4
B) N = 1, H = 5, P = 1, O = 4
C) N = 2, H = 5, P = 1, O = 4
D) N = 2, H = 8, P = 1, O = 4

(28) Carbon monoxide is considered which of the following?    (1 point)
A) atomic element	
B) molecular element
C) molecular compound
D) ionic compound
E) none of the above

(29) Fluorine (F2) is considered which of the following?    (1 point)
A) atomic element	
B) molecular element
C) molecular compound
D) ionic compound
E) none of the above

(30) The ionic compound that forms between potassium and oxygen is    (1 point)
A) K2O.
B) KO.
C) KO2.
D) K2O2.
E) none of the above


(31) In your own words, briefly describe the scientific method. How does it differ from philosophy? (4 points)


















(32) A fictional element has two naturally occurring isotopes with the natural abundances shown here: (3 points)
ISOTOPE
ABUNDANCE
18.0123 amu
40.000%
20.1046 amu
60.000%

Calculate the atomic mass of the isotope. Show all your work. Be sure to use units in your equations and report your answer with the correct number of significant figures.








