Chemistry Exam #1
45 m/s = __________ km/hr
1.6 x 10^2
which species has 54 electrons?
128 Te^2- 52
Which pair of atoms constitutes a pair of isotopes of the same element?
14/6 X 12/6 X
which of the following atomic symbols is incorrect?
14/8 N
using the rules of significant figures, calculate the following (6.167+85)/6.10
15
the correct answer (reported to the proper number of significant figures) to the following is 12.75 x 1.3621
17.37
Barium forms an ion with a charge of __________.
2+
express the number 0.000216 in scientific notation?
2.14x10^-4
The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is ________ amu.
220.4
round the number 0.007222 to three significant figures
0.007
The length of the side of a cube having a density of 12.6 g/ml and a mass of 7.65 g is ________ cm.
0.847
osmium has a density of 22.6 g/cm3. what volume (in cm3) would be occupied by a 21.8 g sample of osmium?
0.965
which of the following metric relationships are incorrect
1 gram= 10^3 kilograms
1 picometer = _____ centimeters
1 x 10^-10
the proper formula for hydronium ion is
H3O+
elements in group 7a are known as the
Halogens
what is the formula of the compound formed between strontium ions and nitrogen ions?
Sr3N2
an isotope, X, of a particular element has an atomic number of 16 and a mass number of 34, therefore:
X is am isotope of sulfur and x has 18 neutrons per atom
the agreement of a particular value with the true value is called?
accuracy
An example of a pure substance is
all of these (elements, compounds, pure water, carbon dioxide)
of the following, the smallest and lightest subatomic particle is the
an electron
the correct name for H2CO3 is
carbonic acid
a method of separation that employs a system with two phases of matter, a mobile phase and a stationary phase is called?
chromotography
____ are substances with constant composition that can be broken down into elements by chemical processes
compounds
the law of constant composition applies to
compounds
Copper and chlorine form an ionic compound whose formula is CuCl2. The name of this compound is ________.
cupric chloride
Of the following, the smallest and lightest subatomic particle is the __________.
electron
cathode rays are
electrons
which one of the following is a pure substance?
elemental oxygen
name three methods for the separation of mixtures
evaporation, distillation, filtration and chromotography
(according to 3 archery targets) which of the following represent having high precision?
figure 3 only
the suffix -ide is used primarily ____
for monatomic anion names
A combination of sand, salt, and water is an example of a
heterogenous mixture
for which of the following can the composition vary?
heterogenous mixture
A solution is also called a
homogeneous mixture
a small amount of salt dissolved in water is an example of a
homogenous mixture
precision refers to
how close a measured number is to other measured numbers
the correct name for HBrO
hypobromous acid
Elements ________ exhibit similar physical and chemical properties.
in the same group of the periodic table
a metric unit for length is
kilometer
the correct name for MgF2 is
magnesium fluoride
When a metal and a nonmetal react, the __________ tends to lose electrons and the __________ tends to gain electrons.
metal, nonmetal
Order the four metric prefixes from smallest to largest
nano>milli>centi>kilo
the subatomic particles located in the nucleus with no overall charges are
neutrons
the correct name for HNO2 is
nitrous acid
in which group do all of the elements have the same number of valence electrons?
none of these
Oxygen is a __________ and nitrogen is a __________.
nonmetal, nonmetal
all atoms of a given element have the same
number of protons
in the periodic table the elements are arranged in
order of increasing atomic number
of the following, _____ contains the greatest number of electrons
p3-
alpha particles beamed at thin metal foil may
pass directly through without changing direction, be slightly diverted by attraction to electrons, and be reflected by direct contact with nuclei (A,B,C)
the name of PCl3 is
phosphorus trichloride
the boiling water is a
physical change because the gaseous water is chemically the same as the liquid
the correct name for K2S is
potassium sulfide
The degree of agreement among several measurements of the same quantity is called __________. It reflects the reproducibility of a given type of measurement.
precision
the correct name for NaHCO3 is
sodium bicarbonate
The state of matter for an object that has both definite volume and definite shape is
solid state
in the symbol below, x/6 C is
the atomic number
in the following list only ______ is not an example of a chemical reaction?
the condensation of water vapor
in the rutherford nuclear atom model,
the heavy subatomic particles, protons and neutrons, reside in the nucleus
which of the following is an example of a quantitative observation
the temperature is 60 C
of the following, only ____ is an extensive property
volume
express the volume 239.7 cm^3 in liters
.2397 L
which combination of protons, neutrons, and electrons is correct for the isotope of copper,63 29Cu
29 p+, 34 n., 29 e-
which of the following is (are) the lowest temperature?
30 F
the distance of 33 km =
3300 m
Round the number 3456.5 to two significant figures.
3500
which one of the following is the highest temperature?
38 C
Consider the numbers 23.68 and 4.12. The sum of these numbers has ____ significant figures, and the product of these numbers has ____ significant figures.
4,3
4.90x10^5 J energy is equal to how many kj?
4.90x10^2
The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is ________ amu.
41.54
an object measuring 0.4500 kilograms will have a mass of _____ grams
450.0
5.6 kilograms contain this many grams?
5.6x10^2
there are ___ electrons, ____ protons, and ____ neutrons in a 132/54 Xe
54, 54, 78
7.7 seconds contain how many picoseconds?
7.7x10^12
a 20.0 mL sample of glycerol has a mass of 25.2 grams. what is the mass if a 57 mL sample of glycerol?
72 g
The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus
75 protons and 110 neutrons
the formula for the compound formed between aluminum ions and phosphate ions is
AlPO4
If the Thomson model of the atom had been correct, Rutherford would have observed:
Alpha particles going through the foil with little to no defection
(13 6 X) in the symbol below, X=
C
what is the molecular formula for octane?
C8H18
Which pair of substances could be used to illustrate the law of multiple proportions?
CO, CO2
Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?
Ca and Sr
explain the main differences between a compound and a mixture
Compounds are those substances which can be created by the chemical combination of two or more elements. Mixtures are those substances that are created by a physical combination of two or more substances.
which one of the following compounds is chromium (III) oxide?
Cr2o3
which of the following compounds is copper(I) chloride?
CuCl
the scientist whose alpha particle scattering experiment led him to conclude that the nucleus of an atom contains a dense center of positive charge is
Ernest Rutherford
which one of the following has the element name and symbol matched correctly
Fe-Iron
Which formula/name pair is incorrect?
Fe2(SO4)3 iron(III) sulfide
the first scientist to show that atoms emit any negative particles was
J.J. Thomson
Which formula/name pair is incorrect?
Mg3N2 magnesium nitrite
Predict the empirical formula of the ionic compound that forms from magnesium and oxygen.
MgO
the charge of an electron was determined in the
Millikan oil drop experiment
which of the following pairs of compounds can be used to illustrate the law of multiple proportions?
NO NO2
of the choices below, which one is not an ionic compound?
PCl5