Significant Figures
Answer the problem with the proper amount of sig figs.
125 × 9.000
1,130 or 1.13x103
How many miles will a person run during a 10 kilometer race?
(0.621 mi=1.00 km)
6 miles
Which of the following is NOT a property of a mixture?
a) The components can be easily separated
b) The original properties of the combined substances are changed
c) The proportion of the components is variable
d) Two or more substances are combined
B
2963 Cu
What is the atomic number and the mass number of the element listed above? How many protons, neutrons, and electrons does it have?
atomic number: 29
mass number: 63
p: 29 n: 34 e: 29
1) H
2) Na
3) Cd
4) P
1) nonmetal
2) metal
3) metal
4) nonmetal
Answer the problem with the proper amount of sig figs.
13.77 + 908.226 + 515
1,437
Complete the two unit conversions:
3779 µg = ? g
1738 km = ? m
3.779 x 10-3 g; 1,738,000 m
A testable explanation to a problem that has not yet been tested is known as
a) data
b) theory
c) fact
d) hypothesis
D
How many protons, neutrons, and electrons are in the following isotope:
Mg-26
protons: 12
neutrons: 14
electrons: 12
What are the symbols for iron, bromine, lithium, oxygen, copper, and chlorine?
Fe, Br, Li, O, Cu, Cl
Answer the problem with the proper amount of sig figs.
118.75/1.534 grams−35.5 grams
41.9
Express a speed of 65 mi/h in SI units (m/s)
hint: 1 mile = 1609.34 m
29 m/s
Calculate the percent by mass of each element in Cesium Fluoride (CsF).
87.5% Cs and 12.5% F
What is the number of protons and electrons for the following ion:
Ca2+
protons: 20
electrons: 18
What are the chemical names for the symbols Xe, F, C, Co, Sn, and B?
Xenon, Fluorine, Carbon, Cobalt, Tin, Boron
A meter has 1000 millimeters in it. How many significant figures does this number have?
The conversion is exact. An infinite number of significant figures
As an instructor is preparing for an experiment, he requires 225 g phosphoric acid. The only container readily available is a 150-mL Erlenmeyer flask. Is it large enough to contain the acid, the density of which is 1.83 g/mL?
Yes, because the acid's volume will be 123 mL
Based on the data below, which student has the most precise data?
Student A Student B Student C
Trial 1- 183.5oC 190.0oC 181.2oC
Trial 2- 185.9oC 183.3oC 182.0oC
Trial 3- 184.6oC 187.1oC 181.7oC
Mean- 184.7oC 186.8oC 181.6oC
Accepted Value- 185oC
Student C, all of their data values are closest to one another
What's the symbol of the ion having 16 protons and 18 electrons?
sulfide ion, S2-
Label each element by what periodic table group they are in:
1) magnesium
2) chlorine
3) xenon
1) alkaline earth metals 2) halogens 3) noble gases
Write these numbers in scientific notation and with proper sig figs: 42,000; 27.0040; 150,000,000; 0.00000003500; 50,000; 0.0205
(hint: the sig figs stay the same as they are in the number above)
4.2 x 104; 2.70040 x 101; 1.5 x 108, 3.500 x 10-8; 5 x 104; 2.05 x 10-2
Find the mass, in pounds, of 1.00 m3 of corn syrup (density of 1.38 g/cm3). Hint: 1 kg=2.20462 lb
3.04 x 103 lb
A pure sample of ammonia contains 14 g of nitrogen and 3 grams of hydrogen. A second sample of pure ammonia contains 28 g nitrogen and 6 g of hydrogen. This is an example of the
a) law of universal gravitation
b) law of multiple proportions
c) law of definite proportions
d) law of mass action
C
Determine the number of protons, neutrons, and electrons in the following isotope:
atomic number 53, atomic mass number 131, charge of 1−
p: 53; n: 78; e: 54
Ag (silver) is in ____ 11 and ____ 5, and is part of the _______.
a) group, period, transition metals/coinage metals
b) group, period, inner transition metals/coinage metals
c) period, group, inner transition metals/coinage metals
e) period, group, transition metals
A