Chapter - 4: Atoms and Elements Flashcards

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1
Q

Groups on periodic table

A

groups contain elements with similar properties in vertical columns

Group numbers are written at the top of each vertical column and they
•use the letter A for representative elements (Groups 1A–8A)•use the letter B for transition elements (Groups 3B–12B)

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2
Q

periods on periodic table

A

periods are horizontal rows of elements, counted from top to bottom of the table as Periods 1−7

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3
Q

Identify the element described by each of the following:
1. Group 7A, Period 4
A. Br B. Cl C. Mn

  1. Group 2A, Period 3
    A. beryllium B. boron C. magnesium
  2. Group 5A, Period 2
    A. phosphorus B. arsenic C. nitrogen
A
  1. Group 7A, Period 4
    A. Br
  2. Group 2A, Period 3
    C. magnesium
  3. Group 5A, Period 2
    C. nitrogen
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4
Q

Metals

A
  • Metals are located to the left.
  • are shiny and ductile
  • are good conductors of heat and electricity
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5
Q

Nonmetals

A
  • Nonmetals are located to the right.
  • are dull, brittle, and poor conductors
  • are good insulators
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6
Q

Metalloids

A
  • Metalloids are located along the heavy zigzag line between the metals and nonmetals.
  • are better conductors than nonmetals but not as good as metals
  • are used as semiconductors and insulators
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7
Q

Electrical Charges in an Atom:

Atoms contain subatomic particles.

A
  • Protons have a positive (+) charge.
  • Electrons have a negative (–) charge.
  • Neutrons are neutral.

Like charges repel and unlike charges attract.

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8
Q

Which of the following subatomic particles fits each of the descriptions below?
proton, neutron, electron

A. found outside the nucleus
B. has a positive charge
C. has mass but no charge

A

A. found outside the nucleus = electron
B. has a positive charge = proton
C. has mass but no charge =neutron

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9
Q

Atomic Number

A

The atomic number
•is a whole number specific for each element
•is the same for all atoms of an element
•is equal to the number of protons in an atom
•appears above the symbol of an element in the periodic table

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10
Q

Atomic Number = Protons in an Atom

A

The atomic number represents the number of protons. For example,
•the atomic number of H is 1; every H atom has one proton
•the atomic number of C is 6; every C atom has six protons
•the atomic number of Cu is 29; every Cu atom has 29 protons

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11
Q

Atoms Are Neutral

A

For neutral atoms, the net charge is zero.
number of protons = number of electrons

Aluminum has 13 protons and 13 electrons. 
The net (overall)charge is zero.       
 13 protons (13+)   +  13 electrons (13–)  = 0
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12
Q

Mass Number

A

The mass number
•represents the number of particles in the nucleus
•is equal to the number of protons + the number of neutrons
•is always a whole number
•does not appear in the periodic table

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13
Q

Number of protons =

A

Number of protons = atomic number

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14
Q

Number of protons +number of neutrons =

A

Number of protons +number of neutrons = mass number

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15
Q

Number of neutrons =

A

Number of neutrons = mass number – atomic number

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16
Q

An atom of lead (Pb) has a mass number of 207.
A. How many protons are in the nucleus?
B. How many neutrons are in the nucleus?
C. How many electrons are in the atom?

A

An atom of lead (Pb) has a mass number of 207.
A. How many protons are in the nucleus?
atomic number = 82; number protons = 82

B. How many neutrons are in the nucleus? mass number – number protons = number neutrons 207 – 82 = 125 neutrons

C. How many electrons are in the atom? An atom is neutral, which means that the number of electrons is equal to the number of protons. An atom of Pb has 82 protons and82 electrons.

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17
Q

Isotopes

A

Isotopes
•are atoms of the same element that have different mass numbers
•have the same number of protons, but different numbers of neutrons

18
Q

Atomic symbol

A

An atomic symbol
•represents a particular isotope of an element
•gives the mass number in the upper left corner and the atomic number in the lower left corner

The atomic symbol indicates the number of protons, neutrons, and electrons in a specific isotope of an element.

19
Q

There are three naturally occurring isotopes of carbon: C-12, C-13, and C-14. Write the atomic symbol for each isotope, and state the number of protons, neutrons, and electrons in each of these isotopes.

Atomic Symbol
Number of Protons
Number of Neutrons
Number of Electrons

A

Atomic sym /#of pro / # of Neu/ # of Elec
12C6 6 6 6
13C6 6 7 6
14C6 6 8 6

20
Q

Write the atomic symbols for atoms with the following subatomic particles:
A.8 protons 8 neutrons 8 electrons
B.17 protons 20 neutrons 17 electrons
C.47 protons 60 neutrons 47 electrons

A

A.8 protons 8 neutrons 8 electrons
16O8

B.17 protons 20 neutrons 17 electrons
37Cl17

C.47 protons 60 neutrons 47 electrons
107Ag47

21
Q

Consider the following pairs of atoms in which X represents the chemical symbol of the element:
A. 15X8 15X7
B. 12X6 14X6
C. 15X7 16X8

1.Which of the pairs are isotopes of the same element?2.In which of the pairs do both atoms have eight neutrons?

A

1.Which of the pairs are isotopes of the same element?
B. 12X6 14X6

Each has 6 protons, so the element is carbon. The different mass numbers indicate that each species has a different number of neutrons. These are isotopes.

2.In which of the pairs do both atoms have eight neutrons?
C. 15X7 16X8

15X7 Number of neutrons = 15 (mass number)- 7(atom number) =8 neutrons

16X8 Number of neutrons = 16(mass number) - 8(atomic number) = 8neutrons

22
Q

Atomic mass

A

The atomic mass of an element is
•listed below the symbol of each element on the periodic table
•calculated based on the weighted average of all naturally occurring isotopes
•based on its comparison to the mass of carbon-12
•not the same as the mass number

23
Q
Using the periodic table, specify the atomic mass of each element.
A.calcium          Fill in the blanks
B.aluminum      Fill in the blanks
C.lead               Fill in the blanks
D.barium          Fill in the blanks
E.iron               Fill in the blanks
A
A.calcium      40.08 atomic mass unit
B.aluminum   26.98 atomic mass unit
C.lead            207.2 atomic mass unit
D.barium        137.3 atomic mass unit
E.iron             55.85 atomic mass unit
24
Q

Calculating Atomic Mass

A

The atomic mass of 35.45 atomic mass unit for chlorine that we see on the periodic table is the average mass of a sample of Cl atoms, although no individual Cl atom actually has this mass. The atomic mass of 35.45 is closer to the mass number of the isotope Cl-35 which indicates a higher percentage of Cl-35 atoms in the chlorine sample.

To calculate atomic mass,
•use an experimental percent abundance of each isotope of the element
•multiply the percent abundance by the atomic mass of that isotope
•sum the total mass of each isotope

25
Q

Lithium has two naturally occurring isotopes, Li-6 and Li-7. If the atomic mass for lithium on the periodic table is 6.941, which isotope of lithium is more abundant?

A

The isotope Li-7 is more abundant because its mass is closer to the atomic mass of Li on the periodic table.

26
Q

There are three naturally occurring isotopes of potassium, K-39, K-40, and K-41. If the atomic mass for potassium on the periodic table is 39.10, which isotope of potassium is most abundant?

A

The isotope K-39 is most abundant because its mass is closest to the atomic mass of K on the periodic table.

27
Q

Identify the group or period that contains Li and Cs.

A

group 1A

The vertical columns are called groups. The elements listed in this problem appear above and below each other in the periodic table, in the first column. This column is named group 1A.

28
Q

Identify the group or period that begins with the element Be.

A

group 2A

Periods on the periodic table begin with elements in group 1A. Since Be is not located in group 1A, Be must be at the beginning of a group. Because Be is located in the second column, it is the element that begins group 2A, one of the groups of representative elements on the periodic table.

29
Q

Identify the group or period that contains the noble gases

A

group 8A

Certain groups of the periodic table have special names. The noble gases are elements located in group 8A. The newer system of assigning numbers to groups in the periodic table refers to this group as group 18.

30
Q

Identify the group or period that contains Al, P, and Cl.

A

period 3

The elements Al , P , and Cl are all located in the same row, or period. The first period contains only two elements: hydrogen and helium; period 2 is the only period that contains the elements Al , P , and Cl .

31
Q

Identify each of the following as describing a proton, a neutron, or an electron.

A. has a −1 charge
B. is attracted to the proton
C. has a mass about the same as that of a proton
D. is found in the nucleus

A

A. has a −1 charge ELECTRONS only
B. is attracted to the proton ELECTRONS only
C. has a mass about the same as that of a proton NEUTRONS only
D. is found in the nucleus PROTONS AND NEUTRONS ONLY

A summary of the characteristics of each particle is shown in the table.

Particle Charge Mass ( amu ) Location in atom
Proton +1 1.007 nucleus
Neutron 0 1.008 nucleus
Electron −1 0.00055 outside nucleus

32
Q

The atomic number gives the number of _______ in the nucleus.

A

Protons

33
Q

In an atom, the number of electrons is equal to the number of _______.

A

Protons

34
Q

Sodium and potassium are examples of elements called _______.

A

Alkali Metals

35
Q

146C

Express your answers as integers separated by commas.

A

Protons=6
Neutrons=8
Electrons=6

36
Q

11448Cd

Express your answers as integers separated by commas.

A

Np,Nn,Ne =

48,66,48

37
Q

15O8

Express your answers as integers separated by commas.

A

Np,Nn,Ne =

8,7,8

38
Q

199Au79

Express your answers as integers separated by commas.

A

Np,Nn,Ne =

79,120,79

39
Q

222Rn86

Express your answers as integers separated by commas.

A

Np,Nn,Ne =

86,136,86

40
Q

136Xe54

Express your answers as integers separated by commas.

A

Np,Nn,Ne =

54,82,54