Deck 1: Elements Compounds

Question 1

Which of the following correctly describes one of the differences between compounds and mixtures?

A) Compounds contain more than one element but mixtures do not.
B) Compounds have a constant composition but mixtures do not.
C) It is easier to separate the elements in a compound than it is to separate the elements in a mixture.
D) All of these statements are true.
E) None of these statements are true.

Answer 1

Compounds have a constant composition but mixtures do not.

Question 2

Which of the following postulates of Dalton's atomic theory is/are still valid today?
(I) Matter consists of particles called atoms.
(II) Atoms are indestructible and indivisible.
(III) All atoms of an element are identical.
(IV) Atoms of different elements differ in mass.
(V) When the atoms of different elements combine to form compounds they combine in simple whole number ratios.

A) All of these statements are still valid today.
B) I and II are still valid, but not III, IV and V.
C) I, II and III are still valid, but not IV and V.
D) I, IV and V are still valid, but not II and III.
E) II and III are still valid, but not I, IV and V.

Answer 2

I, IV and V are still valid, but not II and III.

Question 3

Calculate the number of protons in the average potassium atom if the atomic weight of potassium is 39 amu and the atomic number of this element is 19.

A) 19
B) 20
C) 39
D) 58
E) The number of protons is impossible to determine from this information.

Answer 3

19

Question 4

The earth is constantly bombarded by cosmic rays emitted by the sun. The total energy received in the form of cosmic rays is small - no more than the energy received by the planet from starlight. But the energy of a single cosmic ray is very large, on the order of 200 million kJ/mol. These highly energetic rays react with atoms in the atmosphere to produce neutrons that then react with nitrogen atoms in the atmosphere to produce ¹⁴C, which decays back to ¹⁴N with a half-life of 5730 years by emitting an electron.
What is the difference between ¹⁴C and ¹⁴N atoms?

A) They have the same number of protons but different numbers of neutrons.
B) They have the same number of neutrons but different numbers of protons.
C) They have the same number of neutrons and protons but different numbers of electrons.
D) ¹⁴N has one more proton and one less neutron than ¹⁴C.
E) ¹⁴N has one more neutron and one less proton than ¹⁴C.

Question 5

Which of the following atoms have the same number of neutrons?
(I) ²³³Th (II) ²³⁵U (III) ²³⁸U (IV) ²³⁸Np

A) I and II
B) I, II and IV
C) II and III
D) III and IV
E) All of these atoms have the same number of neutrons.

Question 6

Which statement correctly describes the difference between the ¹²C, ¹³C and ¹⁴C isotopes of carbon?

A) They have the same number of protons but different numbers of electrons.
B) They have the same number of neutrons but different numbers of electrons.
C) They have the same number of electrons but different numbers of protons.
D) They have the same number of protons but different numbers of neutrons.
E) They have the same number of protons, electrons, and neutrons but
Different atomic masses.

Question 7

What is the symbol for the atom or ion that has 34 neutrons, 29 protons, and 27 electrons?

A) ³⁴Se^{2 -}
B) ²⁹Cu²⁺
C) ⁶³Se^{2 -}
D) ⁶³Cu²⁺
E) ²⁷Co²⁺

Question 8

How many electrons are in ⁵²Cr³⁺?

A) 3
B) 21
C) 24
D) 27
E) 28

Question 9

How many protons are in ³²S^2-?

A) 2
B) 14
C) 16
D) 18
E) 32

Question 10

Complete the following table.

Question 11

Complete the following table

Question 12

Complete the table

Question 13

Describe the difference on the atomic scale between the following three forms of oxygen:
O, O₂, O^{2 -} .

Question 14

Which choice gives the diagrams in the order that best represents 2O₂, 4O, and X₃, respectively?

A) A B C
B) C B A
C) B C A
D) B A C
E) None of the above gives the cartoons in the correct order.

Question 15

Atoms are isobaric if they have the same mass. Which of the following atoms or ions are isobaric?

(I) ⁵¹Cr³⁺ (II) ⁵²Cr³⁺ (III) ⁵⁵Mn³⁺ (IV) ⁵⁹Ni⁴⁺ (V) ⁵⁹Co³⁺

A) I and II
B) II and III
C) III and IV
D) IV and V
E) III, IV and V

Question 16

Which of the following correctly describes a Zn²⁺ ion that has a mass number of 65?

A) It contains 28 electrons, 30 protons, and 35 neutrons.
B) It contains 30 electrons, 30 protons, and 35 neutrons.
C) It contains 32 electrons, 30 protons, and 35 neutrons.
D) It contains 35 electrons, 35 protons, and 30 neutrons.
E) It contains 37 electrons, 35 protons, and 30 neutrons.

Question 17

Calculate the number of electrons in a P^3- ion if the mass number of phosphorus is 31 and the atomic number of this element is 15.

A) 12
B) 15
C) 18
D) 31
E) 34

Question 18

Which of the following symbols indicates an atom or ion with 12 protons and 10 electrons?

A) Mg²⁺
B) C⁴⁺
C) O^2-
D) Ne
E) none of these

Question 19

All of the following have the same number of electrons except:

A) K⁺
B) Ca²⁺
C) Al³⁺
D) S^2-
E) Cl^-

Question 20

What is the symbol for the atom or ion that has 26 protons, 30 neutrons, and 24Electrons?

A) ⁵⁶Cr²⁺
B) ⁵⁴Cr²⁺
C) ⁵⁶Fe²⁺
D) ⁵⁴Fe³⁺
E) ⁵⁴Cr

Question 21

How many electrons are present in the ⁷⁷Se^2- ion?

A) 32
B) 34
C) 43
D) 77
E) none of these

Question 22

How many electrons are present in the ¹³⁶Ba²⁺ ion?

A) 56
B) 58
C) 78
D) 134
E) none of these

Question 23

Calculate the number of electrons on a Ce⁴⁺ ion if the atomic number of this
Element is 58 and the mass number of the ion is 140.

A) 54
B) 58
C) 62
D) 136
E) 140

Question 24

Which of the following compounds is composed only of polyatomic ions?

A) NH₄NO₃
B) CaO
C) H₂SO₄
D) NO₂
E) CO₂

Question 25

Which of the following is a nonmetal in period 4?

A) C
B) Ca
C) Se
D) Sr
E) none of these

Question 26

Which of the following elements is neither a metal nor a nonmetal?

A) Na
B) Mg
C) Ga
D) Si
E) P

Question 27

Classify the following elements as metals, nonmetals or semi-metals:
S, Sb, Sc, Se, Sg, Si, Sm, Sn, and Sr.

Question 28

use the data listed below.



-If you were able to select a single atom of oxygen from a naturally occurring sample, what would its mass most likely be?

A) 15.9949 amu
B) 16.9991 amu
C) 17.9992 amu
D) 15.9993 amu
E) none of these

Question 29

use the data listed below.



-If you were able to select 1000 individual atoms of oxygen from a naturally occurring sample, what would be the $\textbf{ average}$ mass of the atoms?

A) 15.9949 amu
B) 16.9991 amu
C) 17.9992 amu
D) 15.9993 amu
E) none of these

Question 30

use the data listed below.


-If you select a $\textbf{ single }$ random atom of Ne from a naturally occurring sample, its mass is most likely to be

A) 19.99244 amu
B) 20.99384 amu
C) 21.99138 amu
D) 20.179 amu
E) 20.000 amu

Question 31

use the data listed below.


-If you select $\textbf{ 100 }$ random atoms of Ne from a naturally occurring sample, their $\textbf{ total }$ mass is most likely to be

A) 1999.244 amu
B) 2099.384 amu
C) 2199.138 amu
D) 2017.9 amu
E) 2000.0 amu

Question 32

What will be the coefficient for HNO₃ when the following equation is balanced?

Ba(OH)₂(aq) + HNO₃(aq) $\rightarrow$ Ba(NO₃)₂(aq) + H₂O(l)

A) 1
B) 2
C) 3
D) 5
E) none of these

Question 33

What will be the coefficient for oxygen when the following equation is balanced?
C₃H₈(g) + O₂(g) $\rightarrow$ CO₂(g) + H₂O(g)

A) 1
B) 2
C) 3
D) 5
E) none of these

Question 34

What will be the coefficient for NH₃ when the following reaction is balanced?
NH₃(g) + O₂(g) $\rightarrow$ N₂(g) + H₂O(l)

A) 1
B) 3
C) 4
D) 5
E) none of these

Question 35

Balance the following equations:
(I) Na₂SO₄(s) + C(s) $\rightarrow$ Na₂S(aq) + CO₂(g)
(II) Mg₃N₂(s) + H₂O(l) $\rightarrow$ Mg(OH)₂(aq) + NH₃(g)

Question 36

The balanced equation for the decomposition of ammonium dichromate has which of the following sets of coefficients?
A (NH₄)₂Cr₂O₇(s) $\rightarrow$ B Cr₂O₃(s) + C N₂(g) + D H₂O(g)

A) A = 2, B = 2, C = 2, D = 4
B) A = 1, B = 1, C = 1, D = 4
C) A = 1, B = 1, C = 1, D = 2
D) A = 1, B = 1, C = 2, D = 2
E) A = B = C = D = 1

Question 37

Calculate the sum of the coefficients in the balanced chemical equation for the following reaction:
A H₂S(g) + B O₂(g) $\rightarrow$ C SO₂(g) + D H₂O(g)

A) 6
B) 8
C) 9
D) 11
E) 17

Question 38

What is the sum of the coefficients when the following chemical equation is balanced?
A Ca₃(PO₄)₂(s) + B C(s) $\rightarrow$ C Ca₃P₂(s) + D CO(g)

A) 6
B) 12
C) 18
D) 20
E) none of the above

Question 39

Which illustration best represents the following equation?

A)
B)
C)
D)
E)