Midterm 1
Chem 305
1) Which statement describes a physical change?
A) winding an alarm clock B) turning on a flashlight
C) digesting your lunch
D) burning the morning toast
2) Which of the following are states of matter?
A) solid B) suspension C) solution D) precipitate
3) Which of the following is a mixture?
A) cough syrup B) iron C) helium D) sodium hydrogen carbonate
4) What is the chemical symbol for chromium?
A) C B) Ca C) Cl D) Cr
5) Caffeine, the active ingredient in coffee, is composed of eight atoms of carbon, ten atoms of hydrogen, and four atoms of nitrogen. The
chemical formula of caffeine is written
A) CHNO B) C8H10N4O2 C) C8H10N4 D) C8H12N4O4
6) Which chemical symbol represents a metallic element?
A) Ar B) Br C) Ca D) H
7) The metric unit used to measure volume is the
A) gram. B) gram per cubic centimeter. C) Kelvin. D) liter.
8) What is the numerical value of 1.2 × 1.222? Express your answer using the correct number of significant figures.
A) 1.5 B) 1.47 C) 1.466 D) 1.4664
9) The number 5.320 × 102 in conventional notation is
A) 532.0. B) 53.20. C) 5.320. D) 0.5320.
10) Which choice best describes the degree of uncertainty in the measurement 16.30 g?
A) The quantity is exact. B) ±1.00 g C) ±0.10 g D) ±0.01 g
11) Which particle has a mass approximately equal to the mass of a proton?
A) atom B) electron C) neutron D) nucleus
12) Where is most of the mass of an atom concentrated?
A) electrons B) neutrons C) nucleus D) orbitals
13) The value for Z for an atom containing 47 protons, 47 electrons, and 60 neutrons is
A) 13. B) 47. C) 60. D) 107.
14) Consider the isotope 35- Br. The atomic number is ________, and the mass number is ________.
A) 79; 35 B) 35; 79 C) 44; 35
D) 35; 44
15)Which element is most likely to have chemical properties similar to those of bromine (atomic number 35)?
A) S (atomic number 16) B) Se (atomic number 34) C) Kr (atomic number 36) D) I (atomic number 53)
16) How many electrons can occupy the shell having n = 4?
A) 2 B) 8 C) 18 D) 32
17) What is the maximum number of electrons that can occupy the 3d orbitals?
A) 2 B) 6 C) 8 D) 10
18) Which of the following subshells consists of five orbitals?
A) 4s B) 4p C) 4d D) 4f
19) The element with the electron configuration 1s2 2s2 2p6 3s2 3p5 is
A) fluorine. B) chlorine. C) carbon. D) potassium.
20) The number of valence electrons in an element with electron configuration
1s2 2s2 2p6 3s2 3p4 is ________.
A) 2 B) 4 C) 6 D) 8
21) The element which has four valence electrons is ________.
A) H B) Na C) Mg D) Si
22) A small negatively charged particle formed when an atom gains one or more electrons is called a(an)
A) anion. B) cation. C) isotope. D) nucleus.
23) The property that describes the ease with which an atom gives up an electron to form a positive ion is
A) atomic number. B) electron affinity. C) electronegativity. D) ionization energy.
24) Which one of the compounds below is most likely to be ionic?
A) SrBr2 B) NO2 C) CBr4 D) H2O
25) Which of the following pairs will form ionic bonds with one another?
A) N, C B) Na, Ca C) Cs, Br D) S, Cl
26) What is the most likely charge on an ion formed by an element with a valence electron configuration of ns2np4?
A) 2- B) 1- C) 2+ D) 4+
Name ________________________________
27) Which of the following ions does not have the same electron configuration as the noble gas neon?
A) O-2 B) F- C) Al+3 D) S-2
28) Elements that are metals usually ________ one or more electrons to form ________, which have a ________ charge.
A) lose; anions; negative B) lose; cations; negative C) lose; cations; positive D) gain; cations; positive
29) Which of the following has the largest size?
A) Ne B) Br C) P D) Al
30) In order to form an octet, an atom of selenium will
A) lose 6 electrons. B) gain 6 electrons. C) lose 2 electrons. D) gain 2 electrons.
Written Part
1.
How many ml in 3.98 gal (4 pts)
2.
How many tons/in2 in 34.50 kg/cm2 (5 pts)
3.
How many micrograms in 4.3 kilograms ( 3 pts)
4.
( 205.56 + 0.169)/453.2 = __________________________ (3,pts)
5.
What was the difference between Thompsons plum pudding model and Rutherfords model of the atom. (5)
6.
Explain how neutrons were discovered. (5)
7.
What are valence electrons (5)
8.
Name the following ionic compounds or write the formula of the compound name.
A.
Calcium nitride ______________________________________________ (2 pts)
B.
Boron sulfate _________________________________________________(2pts)
C.
BaS ________________________________________________________(2 pts)
D.
Co(CO3)2 _____________________________________________________(2 pts)
E.
NH4ClO _______________________________________________________(2 pts)