CHEM Chapter 4: Atoms

Au is the symbol for:

Gold.

The element in this list with chemical properties similar to Magnesium is:

Strontium.

How many protons are in a isotope of sodium with a mass number of 25?:

11.

Consider an isotope of sodium with a mass number of 25. The number of neutrons in this isotope of sodium is:

14.

The maximum number of electrons that may occupy the third energy level is:

18.

What is the correct electron configuration for the lithium atom?:

1s2 2s1.

What is the electron configuration for aluminum?:

1s2 2s2 2p6 3s2 3p1.

What is the electron configuration for potassium (atomic number 19)?:

1s2 2s2 2p6 3s2 3p6 4s1.

Which of the following electron configurations is impossible?:

1s2 2s4 2p6 3s2 3p3.

How many valence electrons are in the electron-dot structures for the elements in group 3A?:

3.

The number of electron levels in a magnesium atom is:

3.

The number of electrons in the outer energy level of a neutral atom of boron (atomic number 5) is:

3.

Consider a neutral atom with 30 protons and 34 neutrons. The atomic number of the element is:

30.

Consider a neutral atom with 30 protons and 34 neutrons. The number of electrons in this atom is:

30.

A sample of chlorine has two naturally occurring isotopes. The isotope Cl-35 (mass 35.0 amu) makes up 75.8% of the sample, and the isotope Cl-37 (mass = 37.0 amu) makes up the 24.3% of the sample. What is the average atomic mass for chlorine?:

35.5 amu.

What is the mass number of an atom of potassium that has 20 neutrons?:

39.

The number of dots in the electron dot structure of carbon is:

4.

The correct symbol for the isotope of the potassium with 22 neutrons is:

41/19 K.

Given the following 41/19 X, 39/19 X, and 39/18 X. Which are isotopes of each other?:

41/19 X and 39/19 X are isotopes of each other.

The number of dots in the electron-dot structure of nitrogen is:

5.

Which of the following gives the correct number of protons, neutrons, and electrons in a neutral atom of 118/50 Sn?:

50 Protons, 68 Neutrons, and 50 Electrons.

Consider a neutral atom with 30 protons and 34 neutrons. The mass number for this atom is:

64.

Which of the following descriptions of a subatomic particle is correct?:

A proton has a positive charge and a mass of approximately 1 amu.

The atomic mass of an element is the equal to:

A weighted average mass of all of the naturally occurring isotopes of the element.

Silver:

Ag.

Aluminum:

Al.

In an atom, the nucleus contains:

All the protons and neutrons.

The elements lithium, sodium, and potassium:

Are in the same group.

The elements sodium, magnesium, and silicon:

Are in the same period of elements.

The Group 8A elements:

Are unreactive and are rarely found in combination with other elements.

Which of the following elements is a noble gas?:

Argon.

The smallest particle of an element that retains the characteristics of the element is a(n):

Atom.

According to the Atomic Theory:

Atoms are neither created nor destroyed during a chemical reaction.

Which element would have physical and chemical properties similar to chlorine?:

Br(Bromine).

What is the symbol of the element in Group 4A and Period 2?:

C(Carbon).

What is the symbol of the element in Period 4 and Group 2?:

Ca(Calcium).

What elements are in hydroxyapatite, Ca5 (PO4)3OH, a major compound in the human bones and teeth?:

Calcium, Phosphorus, Oxygen, and Hydrogen.

Ca is the symbol for:

Calcium.

What is the element with the electron configuration 1s2 2s2 2p6 3s2 3p5?:

Cl(Chlorine).

The atomic size of atoms:

Decreases going across a period.

The ionization energy of atoms:

Decreases going down within a group.

The primary substances of which all other things are composed are:

Elements.

Of the elements: B, C, F, Li, and Na, the element with the highest ionization energy is:

F.

Of the elements: B, C, F, Li, and Na, the element with the smallest atomic radius is:

F.

Of the elements:B, C, F, Li, and Na, the element with the least metallic character is:

F.

A lithium atom is larger than a potassium atom:

False.

An electron has a positive charge:

False.

Ionization energy increases going down a group:

False.

Radon is metal:

False.

Sulfur has 16 valence electrons:

False.

The electron configuration of potassium is 1s2 2s2 2p6 3s1:

False.

The symbol for potassium is P:

False.

Iron:

Fe.

Identify the metalloid in the following list:

Germanium.

Identify the noble gas in the following list:

Helium.

Valence electrons are electrons located:

In the outermost energy level of an atom.

The number of valence electrons found in an atom of a Group A element is equal to:

Its group number.

Potassium:

K.

Semiconductors are located in the periodic table on (or in) the:

Line dividing metals from nonmetals in the table.

Which of the following is a characteristic of nonmetals?:

Low melting points.

Which of the following properties is NOT a characteristic of the Group 1A elements (alkali metals)?:

Most of them are liquids at room temperature.

Of the elements: B, C, F, Li, and Na, the element with the largest atomic radius is:

Na.

Of the elements: B, C, F, Li, and Na, the element with the smallest ionization energy is:

Na.

Of the elements:B, C, F, Li, and Na, the element with the most metallic character is:

Na.

Sodium:

Na.

Which of the following elements is a nonmetal?:

Nitrogen.

What is the element with the abbreviated electron configuration [Kr]5s2 4d8?:

Pd.

The atomic number of atom is equal to the number of:

Protons.

A sample of silicon has three naturally occurring isotopes: Si-28 (mass 28.0 amu); Si-29 (mass 29.0 amu) and Si-30 (mass 30.0 amu). If the average atomic mass of silicon is 28.1 amu, which isotope is the most abundant?:

Si-28.

What element has the electron configuration 1s2 2s2 2p6 3s2 3p2?:

Silicon.

Which of the following elements is a metal?:

Strontium.

Which of the following is a characteristic of the modern periodic table?:

The elements in each group have similar chemical properties.

Ionization energy is:

The energy needed to remove the least tightly bound electron.

The number of neutrons in an atom is equal to:

The mass number - the atomic number.

The electron arrangement of any particular atom shows:

The number of electrons in each energy level.

The mass number of an atom can be calculated from:

The number of protons plus neutrons.

Isotope are atoms of the same element that have:

The same atomic number, but different numbers of neutrons.

In an electron-dot structure of an element, the dots are used to represent:

The valence electrons.

Which of the following is NOT true for the atoms 13^N, 14^N, and 15^N?:

They all have the same mass number.

A sodium atom is larger than a silicon atom:

True.

Atomic size decreases going from left to right within a period:

True.

Chlorine has a higher ionization energy than aluminum:

True.

Chlorine has more metallic character than fluorine:

True.

Chromium is a metal:

True.

Iodine is a metal:

True.

Isotopes have the same atomic number, but different mass number:

True.

Mercury is a metal:

True.

Potassium has one valence electron:

True.

Protons and neutrons are located in the nucleus of an atom:

True.

Sulfur is a nonmetal:

True.

The symbol for gold is Au:

True.

What is the abbreviated electron configuration for nickel ( atomic number 28)?:

[Ar]4s2 3d8.