Ch 12 - test 1

Which has more atoms: a 1-g sample of carbon-12 or a 1-g sample of carbon-13? Explain.

1-g sample of carbon-12

If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains?

12 C 6

The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?

26

If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? Express your answer as an integer. What is the name of this element? Express your answer as a chemical symbol.

99 amu; Tc

How fast does an electron move within an atom?

About 2 million m/s

Rank them in terms of their atomic number, from largest to smallest. Rank from largest to smallest . To rank items as equivalent, overlap them. He Cl Ar

Ar, Cl, He

Which atom is smallest? Ca Sr Mg Be All are the same size.

Be

Rank the three subatomic particles in order of increasing mass: (a) neutron, (b) proton, (c) electron. Rank from least to most. To rank items as equivalent, overlap them.

C, B, A

What is the atomic symbol for the element cobalt? Express your answer as a chemical symbol.

Co

What was Niels Bohr's explanation for the observation of atomic spectra? Electrons could only move in discrete energy steps within an atom. Electrons could not move in an atom. Any photon could excite an electron. Only certain photons with the correct energy could excite the quanta in the nucleus. Nucleons could be excited by different electron energies.

Electrons could only move in discrete energy steps within an atom.

What is the main tenet of Plank's quantum hypothesis? Energy is composed of subatomic particles called quanta. Energy comes in discrete packets of a certain minimum size. Energy can be converted into matter through nuclear quanta. Light is composed of waves that exist only at certain quantum fundamental frequencies. Energy is a continuum, but light is quantized.

Energy comes in discrete packets of a certain minimum size.

Which element has the atomic number 9?

F

Which of the following statements does not describe a proton? It orbits around the nucleus of an atom. It is attracted to negatively charged electrical plates. It has a positive charge equivalent but opposite of an electron's. It is a nucleon. It is much more massive than an electron.

It orbits around the nucleus of an atom.

Which element has the atomic number 12?

Mg

Rank them, from smallest to largest , in terms of size. Rank from smallest to largest. To rank items as equivalent, overlap them. F P Ne

Ne, F, P

How can a hydrogen atom, which has only one electron, have so many spectral lines? One electron can be boosted to many different energy levels. The protons in the nucleus are also giving off various light frequencies. The atomic radius of the hydrogen atom is relatively large. The electron is able to move at various speeds.

One electron can be boosted to many different energy levels.

Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom's size? Electrons contribute more to both the mass and size of an atom. Electrons contribute more to an atom's mass while protons contribute more to its size. Protons contribute more to an atom's mass while electrons contribute more to its size. Protons contribute more to both the mass and size of an atom.

Protons contribute more to an atom's mass while electrons contribute more to its size.

When we breathe we inhale oxygen, O2, and exhale carbon dioxide, CO2, plus water vapor, H2O. Which likely has more mass, the air that we inhale or the same volume of air we exhale? Does breathing cause you to lose or gain weight? The air we inhale has more mass; Breathing causes you to lose weight. The air we inhale has more mass; Breathing causes you to gain weight. The air we exhale has more mass; Breathing causes you to gain weight. The air we exhale has more mass; Breathing causes you to lose weight.

The air we exhale has more mass; Breathing causes you to lose weight.

A cat strolls across your backyard. An hour later, a dog with its nose to the ground follows the trail of the cat. Explain what is going on from a molecular point of view. The dog is following the areas of increased density of the Earth. The cat is leading the dog into a trap. The dog is smelling molecules from the cat. The dog is smelling atoms from the cat

The dog is smelling molecules from the cat.

Since atoms are mostly empty space, why don't objects pass through one another? The electrons on the atoms repel other electrons on other atoms when they get close. The nucleus of one atom attracts the nucleus of a neighboring atom to form a barrier. The nucleus of one atom repels the nucleus of another atom when it gets close. The electrons of one attract the nucleus of a neighboring atom to form a barrier.

The electrons on the atoms repel other electrons on other atoms when they get close.

What do the electron configurations for all the group 18 noble gases have in common? They occupy the same number of shells. Their outermost occupied shells are filled to capacity. They have the same number of electrons. all of the above

Their outermost occupied shells are filled to capacity.

How do we account for the great variety of substances in the world? View Available Hint(s) There are many possible combinations of atoms. Most of these substances are organic compounds. The Earth is 4.5 billion years old. Atoms are incredibly small.

There are many possible combinations of atoms.

Which are older, the atoms in the body of an elderly person or those in the body of a baby? They are of the same age, which is appreciably older than the solar system. An elderly person because they have been around much longer. It depends upon their diet. A baby because this is surely a trick question.

They are of the same age, which is appreciably older than the solar system.

In what sense can you truthfully say that you are a part of every person around you? We are continually exchanging our atoms. There are more people alive now than have ever lived. We all share the same genetic code. We all live on the same planet and share the same resources.

We are continually exchanging our atoms.

How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values? The energy values of an electron only occur where its wave properties and probability clouds are mutually reinforcing. The wave model accounts for the types of orbitals an electron may occupy, not it's energy levels. Electrons are only able to vibrate at particular frequencies. When an electron wave is confined, it is reinforced only at particular frequencies.

When an electron wave is confined, it is reinforced only at particular frequencies.

Which has more potential energy: an electron close to an atomic nucleus or an electron far from an atomic nucleus?

an electron far from an atomic nucleus?

If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element? atomic mass 142 amu; Einsteinium atomic mass, 99 amu; Technetium atomic mass, 99 amu; Radon atomic mass, 137 amu; Barium

atomic mass, 99 amu; Technetium

If two protons and two neutrons are removed from the nucleus of an oxygen atom, a nucleus of which element remains? nitrogen-12 carbon-12 neon-18 carbon-14

carbon-12

Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom?

circle w smallest dot

The elements fluorine, chlorine, and bromine are also known as _______. View Available Hint(s) chalcogens alkali metals halogens noble gases

halogens

The atoms that make your body _______. View Available Hint(s) were created in the womb of your mother. are made from the food you eat were created from geological processes have existed since the start of the universe

have existed since the start of the universe

When we use a scanning probe microscope, do we see atoms directly or only indirectly?

indirectly

Rank them in terms of the number of atoms, from most to least. Rank from most to least. To rank items as equivalent, overlap them. bromine-79 bromine-81 iron-56

iron-56, bromine-79, bromine-81

Are most elements metallic or nonmetallic?

metallic

The following statement describes which subatomic particle best? It does not have an electrical charge.

neutron

Is it possible to see an atom using visible light?

no

What is at the center of every atom?

nucleus

How many electrons are there in the third shell of sodium, Na (atomic number 11)?

one

The following statement describes which subatomic particle best? It is electrically charged.

pro/electron

The following statement describes which subatomic particle best? It is a nucleon.

pro/neutron

Which contributes more to an atom's mass: electrons or protons? Part complete Which contributes more to an atom's size?

protons; electrons