Download Chapter 4 Homework 4 File

Chemistry
Homework 4
Due date:
Assignment: Complete the attached worksheets.
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Part 1: Short Answer
1.
The 3 particles of the atom are:
a. __________________
b. __________________
c. __________________
2. Their respective charges are:
a. _________________
b. _________________
c. _________________
3. The number of protons in one atom of an element determines the atom’s ________________
number.
4. The _____________ of an element is the total number of protons and neutrons in the
________________ of the atom.
5. What is the overall charge of the nucleus?
6. Give the symbol and the number of protons in one atom of:
a.
b.
c.
d.
e.
f.
g.
7.
Lithium _____________________________
Iron ________________________________
Oxygen _____________________________
Krypton _____________________________
Bromine ____________________________
Mercury ____________________________
Helium _____________________________
Give the symbol and the number of electrons in a neutral atom of:
a.
b.
c.
d.
e.
Uranium ____________________________
Boron ______________________________
Chlorine ____________________________
Iodine ______________________________
Xenon ______________________________
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8. Give the symbol and the number of neutrons in one atom of:
a.
b.
c.
d.
e.
f.
g.
Barium ____________________________
Carbon ____________________________
Fluorine ___________________________
Europium __________________________
Bismuth ___________________________
Hydrogen __________________________
Magnesium _________________________
9. Name the element which has the following number of particles:
a.
b.
c.
d.
e.
f.
26 electrons, 29 neutrons, 26 protons _________________________
53 protons, 74 neutrons ____________________________________
2 electrons (neutral atom) __________________________________
20 protons _______________________________________________
82 electrons, 125 neutrons, 82 protons ________________________
0 neutrons __________________________________
10. If you know ONLY the following information, can you ALWAYS determine what the element is?
(Yes/No)
a.
b.
c.
d.
e.
Atomic number _______________________________
Number of neutrons ___________________________
Number of protons ____________________________
Number of electrons in a neutral atom ____________
Mass number ________________________________
Part 2: Complete the table
PROTONS
NEUTRONS
C
13
Be
10
20
Ne
S
33
3
ELECTRONS
Part 3: Matching
_____ 1. proton
a.
the total number of protons and neutrons
_____ 2. atom
b.
the weighted average mass of the atoms in
a naturally occurring sample of an element
_____ 3. mass number
c.
1/12th of the mass of a carbon-12 atom
_____ 4. atomic mass unit
d.
the number of protons in the nucleus of an atom
_____ 5. electron
e.
atoms with the same number of protons but different
number of neutrons
_____ 6. isotopes
f.
negatively charged subatomic particle
_____ 7. atomic number
g.
the smallest particle of an element that retains the
properties of that element
_____ 8. atomic mass
h.
the central part of an atom, containing protons and
neutrons
_____ 9. nucleus
i.
subatomic particle with no charge
_____ 10. neutron
j.
positively charged subatomic particle
Part IV: Multiple Choice
1.
Which of the following is not a part of Dalton’s atomic theory?
a.
b.
c.
d.
All elements are composed of atoms.
Atoms of the same element are alike.
Atoms are always in motion.
Atoms combine in simple whole number ratios to form compounds.
2. The nucleus of an atom is:
a.
b.
c.
d.
Negatively charged and has a low density
Negatively charged and has a high density
Positively charged and has a low density
Positively charged and has a high density
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3. Dalton theorized that atoms are indivisible and that all atoms of an element are identical. We
now know that:
a.
b.
c.
d.
Dalton’s theories are completely correct
Atoms of an element can have different numbers of protons
Atoms are divisible
All atoms of an element are not identical but that must all have the same mass
4. The number of neutrons in the nucleus of an atom can be calculated by:
a.
b.
c.
d.
Adding together the numbers of electrons and protons
Subtracting the number of protons from the number of electrons
Subtracting the number of protons from the mass number
Adding the mass number to the number of protons
5. The sum of the protons and neutrons in an atom equals the:
a.
b.
c.
d.
Atomic number
Number of electrons
Mass number
Atomic mass
6. Which of these statements is false?
a.
b.
c.
d.
Electrons have a negative charge
Electrons have a mass of 1 amu
The nucleus of an atom is positively charged
The neutron is found in the nucleus of an atom
7. An atom of an element with the atomic number 48 and mass number 120 contains:
a.
b.
c.
d.
48 protons, 48 electrons, and 72 neutrons
72 protons, 48 electrons, and 48 neutrons
120 protons, 48 electrons, and 72 neutrons
72 protons, 72 electrons, and 48 neutrons
8. How do the isotopes hydrogen-2 and hydrogen-3 differ?
a.
b.
c.
d.
Hydrogen-3 has one more electron than hydrogen-2.
Hydrogen-3 has two neutrons and hydrogen-2 has only one.
Hydrogen-3 has three protons and hydrogen-2 has two protons.
Hydrogen-2 has no proton and hydrogen-3 has 1 proton.
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9. The number 80 in the name bromine-80 represents:
a.
b.
c.
d.
The atomic number
The mass number
The sum of the protons and electrons
None of these
10. Which of these statements is not true?
a.
b.
c.
d.
Atoms of the same element can have different mass numbers.
The nucleus of an atom has a positive charge.
Atoms of isotopes of an element can have different number of protons.
Atoms are mostly empty space.
11. Relative atomic masses are measured in:
a.
b.
c.
d.
nanograms
grams
anstrograms
amu
12. The behavior of cathode rays produced in a glass tube containing a gas at low pressure led
Thomson to conclude that the rays:
a.
b.
c.
d.
Were not composed of matter
Were composed of positively charged particles
Were composed of negatively charged particles
Were composed of uncharged particles
13. Who discovered the nucleus by bombarding gold foil with positively charged particles and
noting that some particles were widely deflected?
a.
b.
c.
d.
Rutherford
Dalton
Millikan
Thomson
14. A nuclear particle that has about the same mass as a proton, but with no electrical charges is
called a(n)
a.
b.
c.
d.
Nuclide
Neutron
Electron
Isotope
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15. The mass of 1 mole of chromium (atomic mass 51.996 amu) is
a. 12 g
b. 198 g
c. 51.996 g
d. 6.02 * 1023 g
Part V: Calculations: Be sure to round your answers to the correct number of significant figures.
1.
There are five naturally occurring isotopes of the element zinc. The relative abundance and
mass of each are as follows:
Zinc-64
Zinc-66
Zinc-67
Zinc-68
Zinc-70
48.89%
27.81%
4.110%
18.57%
0.6200%
63.929 amu
65.926 amu
66.927 amu
67.925 amu
69.925 amu
Calculate the average atomic mass of zinc.
2.
Convert 4.50 moles of boron to grams of boron.
3. Convert 39.1 grams of silicon to moles of silicon
4.
Convert 78.45 grams of lead to atoms or particles of lead
5.
Convert 3.457 * 10-36 atoms of carbon to grams of carbon
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Part VI: Electron Configurations – Write the electron configurations for the following elements:
1. He
2. N
3. S
4. Si
5. Al
6. Ca
7. Li
8. Be
9. Cl
10. Ne
11. Ar
12. Ca
13. K
14. O
15. F
16. H
17. Mg
18. Na
19. C
20. B
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