UCF CHM1025 Exam 3

What is the isotopic symbol for the silver isotope with 60 neutrons?

Ag-107

What is the isotopic symbol for the silver isotope with 62 neutrons?

Ag-109

What is the isotopic symbol for the uranium isotope with 146 neutrons?

U-238

What is the isotopic symbol for the hydrogen isotope with one neutron?

H-2

What is the atomic symbol for carbon-14 in the form A/Z X?

14/6 C

What is the charge of the ion most commonly formed by potassium (K)?

+1 charge.

What is the charge of the ion most commonly formed by chlorine (Cl)?

-1 charge.

What is the charge of the ion most commonly formed by sodium (Na)?

+1 charge.

What is the charge of the ion most commonly formed by calcium (Ca)?

+2 charge.

What is the charge of the ion most commonly formed by sulfur (S)?

-2 charge.

Magnesium has three naturally occurring isotopes with the following masses and natural abundances. Calculate the average atomic mass.

Mg-24 23.9850 amu 78.99 %

Mg-25 24.9858 amu 10.00 %

Mg-26 25.9826 amu 11.01 %

24.305 amu

How many sulfur atoms are there in 5.52 moles of sulfur?

3.32 x 10^24 sulfur atoms.

How many moles are in 11.8 g of Argon (Ar)?

0.58 mol.

How many moles are in 3.55 g of Zinc (Zn)?

0.054 mol.

How many moles are in 26.1 g of Tantalum (Ta)?

0.144 mol.

How many moles are in 0.211 g of Lithium (Li)?

0.03 mol.

What is the mass in grams of 2.3×10^−3 mol of Antimony (Sb)?

2.80 g.

What is the mass in grams of 0.0355 mol of Barium (Ba)?

4.87 g.

What is the mass in grams of 43.9 mol of Xenon (Xe)?

5763.631

What is the mass in grams of 1.3 mol of Tungsten (W)?

238.99 g.

An element has two naturally occurring isotopes. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and isotope 2 has a mass of 122.9042 amu. Find the atomic mass of this element and identify it.

Antimony (Sb) 121.75 amu.

Classify Sodium (Na) as an alkali metal, alkaline earth metal, halogen, or noble gas.

Alkali metal.

Classify Iodine (I) as an alkali metal, alkaline earth metal, halogen, or noble gas.

Halogen.

Classify Calcium (Ca) as an alkali metal, alkaline earth metal, halogen, or noble gas.

Alkaline earth metal.

Classify Barium (Ba) as an alkali metal, alkaline earth metal, halogen, or noble gas.

Alkaline earth metal.

Classify Krypton (Kr) as an alkali metal, alkaline earth metal, halogen, or noble gas.

Noble gas.

Which has the greatest number of atoms? 10.0g of Mg, He, P, or Ba?

10.0 g of He.

Classify H2O as ionic or molecular.

Molecular compound.

Classify CaCl2 as ionic or molecular.

Ionic compound.

Classify CO2 as ionic or molecular.

Molecular compound.

Classify N2O5 as ionic or molecular.

Molecular compound.

Classify NaCl as ionic or molecular.

Ionic compound.

Classify MgBr2 as ionic or molecular.

Ionic compound.

How many moles are there in 42.6 g of nitrogen (N)?

3.04 mol.

How many moles of aluminum do 3.7×10^24 aluminum atoms represent?

6.14 mol.

Classify CO2 as ionic or molecular.

Molecular compound.

Classify NiCl2 as ionic or molecular.

Ionic compound.

Classify NaI as ionic or molecular.

Ionic compound.

Classify PCl3 as ionic or molecular.

Molecular compound.

What tiny things are in the nucleus of an atom?

Protons and neutrons.

What tiny things orbit around the nucleus of an atom?

Electrons.

True or False? The charge on an ion is from the loss or gain of protons.

False

What is a diatomic ion?

a. an ion that must exist in a pair

b. an ion with 2 electrons

c. An ion with 2 neutrons

d. an ion with an atomic mass of 2 amu

a. an ion that must exist in a pair

Isotopes of an atom have a different amount of ___________ as the original atom.

a. Protons

b. Neutrons

c. Electrons

d. quarks

b. neutrons

An element A has 2 isotopes, one isotope (A1) has a mass of 25 and the other (A2) has a mass of 30. The real atomic mass of A is 26. Which Isotope has the greater abundance?

a. A1

b.A2

c. They’re equal

d. not enough information

a. A1

Calculate the number of atoms in one mole of Rb.

6.022 × 10²³

Calculate the number of atoms in one mole of Ge.

6.022 × 10^24

Calculate the number of atoms in one mole of U.

6.022 × 10²³

Calculate the number of atoms in one mole of H.

tbc

Write the group name for Group 1.

Alkali Metals

Write the group name for Group 2.

Alkaline Earth Metals

Write the group name for Group 17.

Halogens

Write the group name for Group 18.

Noble Gases

What block are transition metals in?

d block

What block is Potassium (K) in?

s block

What block is Flourine (F) in?

p block

What block is Lanthanum (La) in?

f block

Name all diatomic ions:

H2, N2, O2, F2, Cl2, Br2, I2,.

Identify the following elements as Metals, Metalloids, and non-metals: Sr

Metal

Identify the following elements as Metals, Metalloids, and non-metals: Ge

Metalloid

Identify the following elements as Metals, Metalloids, and non-metals: Cl

Non-metal

Identify the following elements as Metals, Metalloids, and non-metals: C

Non-metal

Metals are _________. (choose all correct answers)

a. ductile

b. brittle

c. conductors

d. ready to make positive ions

e. Exhibiting Photoelectric and thermoionic effect

a. ductile, c. conductors, d. ready to make positive ions, e. Exhibiting Photoelectric and thermoionic effect.

Non-metals are __________. (choose all correct answers)

a. Thermal Conductors

b. Electric insulators

c. brittle

d. malleable

e. exhibiting photoelectric and thermoionic effect

b. Electric insulators and c. brittle

Ozone (O3) is an ____________ of Elemental oxygen (O2).

a. isotope

b. Allotrope

c. ion

d. atomic charge

b. allotrope

The products of a chemical reaction contain the same type and number of atoms that were in the reactants. This is ....

a. the Law of Conservation of Matter

b. the Periodic law

c. the Stoichiometric law

d. the Atomic Theory

a. the Law of Conservation of Matter

In Dalton's original atomic theory, which is the incorrect one?

a. Atoms of one element can readily change into atoms of another element.

b. Atoms of the same element have the same mass.

c. Each element is composed of tiny particles called atoms.

d. Atoms combine in simple ratios to form compounds.

a. Atoms of one element can readily change into atoms of another element.

In relation to electrical charges

a. a positive and a negative charge will repel each other.

b. two negative charges will attract each other.

c. two positive charges will attract each other.

d. a positive and a negative charge will attract each other

d. a positive and a negative charge will attract each other

Select the correct statement.

a. The electron is present in all atoms and it is a positively charged particle with a relatively high mass.

b. The electron is present in all atoms and it is a negatively charged particle with a low mass.

c. The electron is present in all atoms and it has no charge.

d. The electron is present in some atoms and it is a negatively charged particle with a low mass.

b. The electron is present in all atoms and it is a negatively charged particle with a low mass.

In relation to the nuclear theory of the atom, which is correct?

a. The nucleus is negatively charged.

b. Most of the volume of the atom is made up of the nucleus.

c. The nucleus of the atom is neutral.

d. The atom is electrically neutral.

d. The atom is electrically neutral.

In relation to the structure of the atom, which is incorrect?

a. The nucleus contains neutral particles called neutrons.

b. The nucleus of the atom is small so it must be low in mass.

c. The nucleus is small but accounts for over 99% of the mass of the atom.

d. The nucleus contains positively charged particles called protons.

b. The nucleus of the atom is small so it must be low in mass.

Select the correct statements (more than one).

a. The atom has no overall charge because there more neutrons than protons.

b. The electron is assigned a charge of -1 and the proton is assigned a charge of +1.

c. All atoms are composed of protons, neutrons and electrons.

d. The charge of the proton and the electron are the same.

b. The electron is assigned a charge of -1 and the proton is assigned a charge of +1.

c. All atoms are composed of protons, neutrons and electrons.

What is the subatomic particle that is used to identify an element?

a. Electron

b. Proton

c. Cation

d. Neutron

b. Proton

The atomic number of an atom corresponds to .....

a. the number of electrons.

b. the number of protons.

c. the mass of the atom.

d. the number of neutrons.

b. the number of protons.

The atom of which element contains 83 protons in its nucleus?

a. Ce (cerium)

b. Mn (manganese)

c. Bi (bismuth)

d. Cs (cesium)

c. Bi (bismuth)

Atoms of the same element having different numbers of neutrons are called..

a. isotopes

b. allotropes

c. atomic mass units (amu)

d. anions

a. isotopes

Select the statement that is not true.

a. The different isotopes of an element generally exhibit the same chemical behavior.

b. The mass number is the sum of the number of protons and neutrons in an atom.

c. Ne-20 means there are 20 neutrons in the neon atom.

d. The number of neutrons is the difference between the mass number and the atomic number.

c. Ne-20 means there are 20 neutrons in the neon atom.

How many protons and neutrons are present in Au-198?

a. 79 protons and 119 neutrons

b. 70 protons and 128 neutrons

c. 89 protons and 109 neutrons

d. 98 protons and 100 neutrons

a. 79 protons and 119 neutrons

In the formation of ions, what is correct?

a. A lithium atom generally gains a proton to form Li+.

b. A lithium atom generally loses an electron to form Li+.

c. A lithium atom generally gains an electron to form Li+.

d. A lithium atom generally gains an electron for form an anion.

b. A lithium atom generally loses an electron to form Li+.

If selenium gains two electrons, what is the charge on the resulting ion?

a. Se2-

b. Se2+

c. Se3-

d. Se+

a. Se2-

Which of the following is not a typical property of a metal?

a. loses electrons in chemical changes

b. gains electrons in chemical changes

c. ductility: can be made into wires

d. good conductor of heat and electricity

b. gains electrons in chemical changes

Which of the following are not typical properties of a nonmetal? More than one.

a. loses protons to form anions.

b. loses electrons to form cations.

c. gains electrons in chemical changes.

d. poor conductor of heat and electricity.

a. loses protons to form anions.

b. loses electrons to form cations.

This is in relation to the periodic table. Select the correct information.

a. The alkali metals are group 1 metals and are very reactive.

b. The alkaline earth metals are group 2 metals and are fairly unreactive.

c. Helium is a noble gas. It is chemically stable so it forms compounds with other elements.

d. Main group elements have properties similar to transition elements in that they tend to have properties that tend to be predictable.

a. The alkali metals are group 1 metals and are very reactive.

If the elements are arranged in terms of increasing atomic mass, some of their properties repeat periodically. This is known as the ....

a. Coulombic law

b. elemental rule

c. periodic law

d. nuclear law

c. periodic law

Select the correct statement.

a. A metal in a main group tends to lose electrons, forming a cation with the same number of electrons as the nearest noble gas.

b. A metal in a main group tends to gain electrons, forming an anion with the same number of electrons as the nearest noble gas.

c. A metal in a main group tends to gain electrons, forming a cation with the same number of electrons as the closest noble gas.

d. A nonmetal in a main group tends to lose electrons, forming a cation with the same number of electrons as the nearest noble gas.

a. A metal in a main group tends to lose electrons, forming a cation with the same number of electrons as the nearest noble gas.

An element has four naturally occurring isotopes shown. What is the atomic mass of the element?

Isotope Mass (amu) Abundance (%)

A 135.90714 0.19

B 137.90599 0.25

C 139.90543 88.43

D 141.90924 11.13

a. 137.3 amu

b. 140.1 amu

c. 138.9 amu

d. 144.2 amu

b. 140.1 amu

The atomic mass of Cu is 63.546 amu. This means that.....

a. Cu has two isotopes with masses equal to 63.546 amu.

b. Cu has two isotopes with masses greater than 63.546 amu.

c. Cu has an isotope with a mass of 63.546 amu.

d. Cu has two or more isotopes, at least one with a mass greater than 63.546 amu, and at least one with a mass less than 63.546 amu.

d. Cu has two or more isotopes, at least one with a mass greater than 63.546 amu, and at least one with a mass less than 63.546 amu.

What is the average mass in grams, of one platinum atom?

a. 3.239x10^-22 g

b. 1.18039x10^-21 g

c. 3.0869x10^21 g

d. 195.05 g

a. 3.239x10^-22 g

What is the number of atoms in 97.552 g of tin?

a. 7.148x10^25 tin atoms

b. 4.948x10^23 tin atoms

c. 3.95x10^-23 tin atoms

d. 118.71 tin atoms

b. 4.948x10^23 tin atoms

How many moles of Al are present in 3.7 x 10^24 aluminum atoms?

a. 26.2 mol

b. 0.17 mol

c. 13 mol

d. 6.1 mol

d. 6.1 mol

What is the radius (in cm) of a pure copper sphere that contains 1.14 x 1024 copper atoms? [The volume of a sphere is (4/3)r3 and the density of copper is 8.96 g/cm3.]

a. 1.47 cm

b. 13.5 cm

c. 3.46 cm

d. 3.18 cm

a. 1.47 cm