Chapter 8 & 9 Quiz

The number of atoms in a molecule of ammonium sulfate, (NH4)2SO4, is 4. 10. 14. 15.

15.

The formula of a compound formed when aluminum (Al) combines with oxygen (O) is AlO Al3O2 Al2O2 Al2O3

Al2O3

What is the octet rule?

Atoms have a tendency to gain or lose electrons to acquire a structure of eight electrons in the outer orbital.

The sulfate ion is (SO4)2- so the formula for calcium sulfate would be CaSO4 Ca2SO4 Ca2(SO4)2 Ca2(SO4)3

CaSO4

What is the difference between an ionic and a covalent bond?

Electrons are transferred to form ionic bonds, shared to form covalent bonds.

What is the main problem with a solar system model of the atom? --Protons would be required to emit electromagnetic radiation when accelerated. -A solar system model requires a massless, positively charged matrix and there is no evidence that this exists. -Electrons moving in a circle would be accelerating, would lose energy, and would therefore not be able to maintain their orbits.

Electrons moving in a circle would be accelerating, would lose energy, and would therefore not be able to maintain their orbits.

What is the difference between a hydrogen atom in the ground state and one in an excited state? -Electrons must acquire energy to move from excited state to ground state. -Electrons in ground states cannot leave allowed orbits. -Electrons lose energy when moving from a ground state to an excited state. -Ground state has electrons in lowest possible energy state; excited states have electrons with higher energies.

Ground state has electrons in lowest possible energy state; excited states have electrons with higher energies.

Is the mass of an isotope a whole number? -Yes, it is a whole number because it is the number of protons, neutrons, and electrons in an atom. -Yes, it is a whole number because it is the number of protons in an atom. -No, electrons do not contribute to the mass. -No, it is the relative mass of an isotope compared to carbon−12.

No, it is the relative mass of an isotope compared to carbon−12.

What is the difference between a polar covalent bond and a nonpolar covalent bond?

Polar the electrons are shared unequally nonpolar the electrons are shared equally.

Is an atomic number a whole number? -Yes, it can only be a whole number because it is the number of neutrons in an atom. -Yes, it can only be a whole number because it is the number of protons in an atom. -No, it cannot be a whole number because a nucleus contains neutrons as well as protons. -No, it cannot be a whole number because it can gain or lose electrons.

Yes, it can only be a whole number because it is the number of protons in an atom.

Ionic bonds are usually composed of two metals. two nonmetals. a metal and a nonmetal. a metal and a semiconductor.

a metal and a nonmetal.

According to the equation de Broglie derived to describe matter waves, doubling the velocity of an electron would result in less momentum. a greater mass. a smaller wavelength. an unchanged wavelength and mass.

a smaller wavelength.

One reason the Bohr model of the atom failed was because it did not explain why... accelerating electrons do not emit electromagnetic radiation. moving electrons have a greater mass. electrons in the orbits of an atom have negative energies. electrons in greater orbits of an atom have greater velocities.

accelerating electrons do not emit electromagnetic radiation.

An atom of an element belonging to the halogen family has one outer electron. two outer electrons. all outer electrons but one. all outer electrons.

all outer electrons but one.

An atom of an element belonging to the noble gas family has one outer electron. two outer electrons. all outer electrons but one. all outer electrons.

all outer electrons.

Elements combine in fixed mass ratios to form compounds. This must mean that elements... are made up of continuous matter without subunits. are composed of discrete units called atoms. have unambiguous atomic numbers. are always chemically active.

are composed of discrete units called atoms.

The smallest unit of an element that can exist alone or in combination with other elements is the... atom. molecule. ion. electron.

atom.

The modern periodic law is based on... atomic number. atomic mass. atomic weight. chemical activity.

atomic number.

The weighted average of the masses of the stable isotopes of an element as they occur in nature is called the... atomic number. atomic mass. atomic weight. mass number.

atomic weight.

Covalent bonds are formed when... electrons are transferred from the excited to the ground state. electrons are transferred from the ground state to the excited state. electrons are transferred between atoms. atoms share electrons.

atoms share electrons.

The masses of all isotopes are based on a comparison to the mass a particular isotope of... hydrogen. carbon. oxygen. uranium.

carbon.

The electron was discovered through experiments with... electricity. light. radio waves. radioactivity.

electricity.

The first part of an atom to be discovered was the... proton. neutron. electron. nucleus.

electron.

Ionic bonds are formed when electrons are transferred from the excited to the ground state. electrons are transferred from the ground state to the excited state. electrons are transferred between atoms. atoms share electrons.

electrons are transferred between atoms.

What is similar about the Bohr model of the atom and the quantum mechanics model? Both consider -electrons to be a particle in a definite position at a given time. -electrons to be spread out in space that can be described by quantum numbers. -electrons to be particles moving in circular orbits. -electrons to emit a photon when moving from a higher state to a lower state.

electrons to emit a photon when moving from a higher state to a lower state.

Most of the volume of an atom is occupied by... electrons. protons. neutrons. empty space.

empty space.

Chemical energy is stored within molecules as thermal energy. internal activation energy. internal potential energy. kinetic energy of the nucleus.

internal potential energy.

If the absolute difference in electronegativity between two bonded atoms is 2.0, the type of bond is ionic. polar covalent. covalent. none.

ionic.

The sum of the number of protons and neutrons in the nucleus of an atom is called the... atomic number. atomic mass. atomic weight. mass number.

mass number.

Isotopes are atoms of an element with identical chemical properties but with different... numbers of protons. masses. numbers of electrons. atomic numbers.

masses.

An atom of an element belonging to the alkali metal family has... one outer electron. two outer electrons. all outer electrons but one. all outer electrons.

one outer electron.

The idea of matter waves, as reasoned by de Broglie, describes a wavelike behavior of any particle, moving or not. particle that is moving. charged particle that is moving. particle that is stationary.

particle that is moving.

The atomic number of an atom identifies the number of... protons. neutrons. quantum orbits. excited states.

protons.

The nucleus was discovered through experiments with... electricity. light. radio waves. radioactivity.

radioactivity.

Which of the following cannot be broken down to anything simpler? water table salt silver sugar

silver

Each family, or group of elements in a vertical column of the periodic table has elements with chemical characteristics that are... exactly the same. similar. different. exactly opposite.

similar

Ozone is a form of oxygen that is... monatomic. diatonic. triatomic. tetratomic.

triatomic.

Metallic bonds are usually composed of two metals. two nonmetals. a metal and a nonmetal. a metal and a semiconductor.

two metals.

Covalent bonds are usually composed of two metals. two nonmetals. a metal and a nonmetal. a metal and a semiconductor.

two nonmetals.

How are variable-charge ions identified in the modern systematic system for naming compounds?

with the English name of a metal followed by Roman numerals indicating the charge number