atomic concepts.....aim 2

what are the subatomic particles?

.....aim 1

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aim 3.....

 

HW From textbook “CHEMISTRY a Contemporary Approach”

 

 

See table O for the charge and mass of the three subatomic particles.

  

                       

Problems

Find the number of  p, n, e-, and the nuclear charge for all the elements in group 1 of the periodic table.

 

The atomic mass of an atom can be represented in three different ways.

Example

Carbon-14, 14C, and C-14 

Problems

Represent all the elements in group 2 in three different ways

 

Atoms of the same elements can have different mass

Example

H-1, H-2, and H-3

When a neutral atom loses one or more electrons it becomes a positive ion or cation and is smaller than the neutral atom.

Example:

                                                       

 

 

When a neutral atom gains one or more electrons it becomes a negative ion or anion and is larger than the neutral atom.

Example:

 

                                                                                               

Problems

Find the number of p, n, and e- in the following species.

Ti2+, K+, N3-, Br-, Xe6+, H+, and H-

 

TEST YOUR UNDERSTANDING

1/07

1 Which subatomic particles are located in the nucleus of a neon atom?

        (1) electrons and positrons     (2) electrons and neutrons     (3) protons and neutrons     (4) protons and electrons

2 The total mass of the protons in an atom of gold-198 is approximately

        (1) 79 atomic mass units     (2) 119 atomic mass units     (3) 198 atomic mass units     (4) 277 atomic mass units

15 Compared to a phosphorus atom, a P 3– ion has

        (1) more electrons and a larger radius  (2) more electrons and a smaller radius

        (3) fewer electrons and a larger radius (4) fewer electrons and a smaller radius

6/07

2 What is the total charge of the nucleus of a carbon atom?

        (1) –6         (2) 0         (3) +6         (4) +12

4 Which two particles each have a mass approximately equal to one atomic mass unit?

        (1) electron and neutron     (2) electron and positron     (3) proton and electron     (4) proton and neutron

8 When an atom loses one or more electrons, this atom becomes a

        (1) positive ion with a radius smaller than the radius of this atom (2) positive ion with a radius larger than the radius of this atom

        (3) negative ion with a radius smaller than the radius of this atom (4) negative ion with a radius larger than the radius of this atom

33 What is the total number of neutrons in an atom of Fe-57?

        (1) 26         (2) 31        (3) 57      (4) 83

35 What is the total number of electrons in a Mg2+ ion?

        (1) 10         (2) 12         (3) 14         (4) 24

8/07

2 An atom is electrically neutral because the

        (1) number of protons equals the number of electrons         (2) number of protons equals the number of neutrons

        (3) ratio of the number of neutrons to the number of electrons is 1:1   (4) ratio of the number of neutrons to the number of protons is 2:1

31 What is the net charge on an ion that has 9 protons, 11 neutrons, and 10 electrons?

        (1) 1+         (2) 2+         (3) 1–         (4) 2–

32 Which two particles make up most of the mass of a hydrogen-2 atom?

        (1) electron and neutron     (2) electron and proton     (3) proton and neutron     (4) proton and positron

1/06

3 The charge of a beryllium-9 nucleus is    (1) +13     (2) +9     (3) +5    (4) +4

11 Compared to a calcium atom, the calcium ion Ca2+ has  (1) more protons (2) fewer protons  (3) more electrons  (4) fewer electrons

29 When an atom becomes a positive ion, the radius of the atom    (1) decreases    (2) increases    (3) remains the same

51 What is the total number of neutrons in an atom of aluminum-27?

52 Explain, in terms of atomic structure, why the atomic radius of iodine is greater than the atomic radius of fluorine.

6/06

1 Which notation represents an atom of sodium with an atomic number of 11 and a mass number

       

12 Which changes occur as a cadmium atom, Cd, becomes a cadmium ion, Cd2+?

    (1) The Cd atom gains two electrons and its radius decreases.    (2) The Cd atom gains two electrons and its radius increases.

    (3) The Cd atom loses two electrons and its radius decreases.    (4) The Cd atom loses two electrons and its radius increases.

32 What is the total number of electrons in a S2– ion? (1) 10     (2) 14     (3) 16     (4) 18

34 Compared to an atom of phosphorus-31, an atom of sulfur-32 contains

    (1) one less neutron     (2) one less proton     (3) one more neutron    (4) one more proton

8/06

30 An atom of potassium-37 and an atom of potassium-42 differ in their total number of   (1) electrons (2) neutrons (3) protons (4) positrons

31 What is the mass number of an atom that has six protons, six electrons, and eight neutrons? (1) 6 (2) 12 (3) 14 (4) 20

32 Which diagram represents the nucleus of an atom of Al-27?

       

33 A student constructs a model for comparing the masses of subatomic particles. The student selects a small, metal sphere with a mass of 1 gram to represent an electron. A sphere with which mass would be most appropriate to represent a proton?

1/05

2 Which subatomic particle will be attracted by a positively charged object?

                (1) proton (2) neutron (3) electron (4) positron

4 Which two particles have approximately the same mass?

                (1) proton and neutron (2) proton and electron (3) neutron and electron (4) neutron and positron

13 When a lithium atom forms an Li+ ion, the lithium atom

                (1) gains a proton (2) gains an electron (3) loses a proton (4) loses an electron

31 What is the total number of neutrons in the nucleus of a neutral atom that has 19 electrons and a mass number of 39?

                (1) 19 (2) 20 (3) 39  (4) 58

36 How many electrons are in an Fe2+ ion?   (1) 24 (2) 26 (3) 28 (4) 56

6/05

2 Compared to a proton, an electron has

                    (1) a greater quantity of charge and the same sign  (2) a greater quantity of charge and the opposite sign

                    (3) the same quantity of charge and the same sign (4) the same quantity of charge and the opposite sign

11 As a chlorine atom becomes a negative ion, the atom

                    (1) gains an electron and its radius increases (2) gains an electron and its radius decreases

                    (3) loses an electron and its radius increases (4) loses an electron and its radius decreases

34 Which symbol represents a particle that has the same total number of electrons as S2–?     (1) O2–   (2) Si   (3) Se2–   (4) Ar

1/04

1 A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is  (1) 1 (2) 11 (3) 12 (4) 23

33 What is the total number of electrons in a Cr3+ ion? (1) 18 (2) 21 (3) 24 (4) 27

6/04

2 Which statement is true about the charges assigned to an electron and a proton?
        (1) Both an electron and a proton are positive.  (3) An electron is negative and a proton is positive.

        (2) An electron is positive and a proton is negative. (4) Both an electron and a proton are negative.

4 What is the charge of the nucleus in an atom of oxygen-17? (1) 0 (2) -2 (3) +8 (4) +17

34 How many electrons are contained in an Au3+ ion? (1) 76 (2) 79 (3) 82 (4) 197

8/04

1 Which of these phrases best describes an atom?

                (1) a positive nucleus surrounded by a hard negative shell (2) a positive nucleus surrounded by a cloud of negative charges

                (3) a hard sphere with positive particles uniformly embedded (4) a hard sphere with negative particles uniformly embedded

2 Which statement is true about a proton and an electron?

                (1) They have the same masses and the same charges. (2) They have the same masses and different charges.

                (3) They have different masses and the same charges. (4) They have different masses and different charges.

34 What is the total number of electrons found in an atom of sulfur?  (1) 6 (2) 8 (3) 16 (4) 32

36 The nucleus of an atom of cobalt-58 contains

                (1) 27 protons and 31 neutrons (2) 27 protons and 32 neutrons (3) 59 protons and 60 neutrons (4) 60 protons and 60 neutrons

70 What is the total number of electrons in a potassium ion ,K+?

1/03

1 Given the equation below:  This equation represents the formation of a

(1) fluoride ion, which is smaller in radius than a fluorine atom (3) fluorine atom, which is smaller in radius than a fluoride ion

(2) fluoride ion, which is larger in radius than a fluorine atom (4) fluorine atom, which is larger is radius than a fluoride ion

2  Which statement best describes electrons?

(1) They are positive subatomic particles and are found in the nucleus.

(2) They are positive subatomic particles and are found surrounding the nucleus.

(3) They are negative subatomic particles and are found in the nucleus.

(4) They are negative subatomic particles and are found surrounding the nucleus.

3  In which list are the elements arranged in order of increasing atomic mass?

                (1) Cl, K, Ar            (2) Fe, Co, Ni                  (3) Te, I, Xe                                 (4) Ne, F, Na

6/03

1 The atomic number of an atom is always equal to the number of its

        (1) protons, only (2) neutrons, only (3) protons plus neutrons   (4) protons plus electrons

2 The nucleus of an atom of K-42 contains

                (1) 19 protons and 23 neutrons     (2) 19 protons and 42 neutrons

                (3) 20 protons and 19 neutrons     (4) 23 protons and 19 neutrons

3 What is the total number of electrons in a Cu+ ion? (1) 28 (2) 29  (3) 30 (4) 36

4 After a neutral sulfur atom gains two electrons, what is the resulting charge of the ion?

8/03

2 Which particles are found in the nucleus of an atom? (1) electrons, only (2) neutrons, only (3) protons and electrons (4) protons and neutrons

36 What is the total number of neutrons in an atom of an element that has a mass number of 19 and
an atomic number of 9? (1) 9 (3) 19 (2) 10 (4) 28

6/02

1 Base your answers on the information below.

In the modern model of the atom, each atom is composed of three major subatomic (or fundamental) particles.

a) Name the subatomic particles contained in the nucleus of the atom

b) State the charge associated with each type of subatomic particle contained in the nucleus of the atom.

c) What is the net charge of the nucleus?

2 The number of neutrons in the nucleus of an atom can be determined by

(1) adding the atomic number to the mass number  (2) subtracting the atomic number from the mass number

(3) adding the mass number to the atomic mass  (4) subtracting the mass number from the atomic number

3 As an atom becomes an ion, its mass number         (1) decreases                (2) increases                 (3) remains the same

8/02

Electron affinity is defined as the energy released when an atom and an electron react to form a negative ion. The data for Group I elements are presented below.

Draw a graph to show the relationship between each member of Group 1 and its electron affinity by following the directions below.

a) Label the y-axis "Electron Affinity" and choose an appropriate scale. Label the x-axis "Atomic Number" and choose an appropriate scale.   

b) Plot the data from the data table and connect the points with straight lines.

c) Using your graph, estimate the electron affinity of Rb, in kilojoules/mole.  

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