Chapter 4 Video Exam

How does Rutherford's model of the atom explain why some of the alpha particles directed at the gold foil were deflected straight back toward the source?

The atomic nucleus is very small but dense and carries a positive electric charge.

What property of an electron makes it possible to use electron microscopes?

They have shorter wavelengths than visible light.

Does a shell have to contain electrons in order to exist?

Two of the above are reasonable answers.

Why can't we see atoms?

We see with light energy and the wavelength is larger than the object and so it is not reflected.

From which of the following atoms would removing an electron be the most difficult?

Xe

Which of the following concepts underlies all the others: ionization energy, effective nuclear charge, atomic size.

effective nuclear charge

The ________ represents the complete range of frequencies of light energy from radio waves to gamma rays.

electromagnetic spectrum

Rank the following by the relative amounts of energy, from most energetic to least:

gamma rays, blue light, red light, radio waves

Which experiences a greater effective nuclear charge, an electron in the outer shell of neon (atomic number 10) or an electron in the outer shell of sodium (atomic number 11)?

neon because of less inner shell shielding

Would you use a physical model or a conceptual model to describe the following: a gold coin, dollar bill, car engine, air pollution, virus, spread of sexually transmitted disease?

physical model-gold coin, car engine, virus; conceptual model-air pollution, spread of sexually transmitted disease; dollar bill, which could represent wealth, may well be described by either model.

The electron configuration of any neutral group 1 element always ends with ________.

s1

Using the following generic atom description, choose the correct method for determining the number of neutrons.

subtract G from F

The ray of light within a neon sign bends when a magnet is held up to it because ________.

the light arises from the flow of electron within the tube

Oxygen, O, (number 8), sulfur, S, (number 16), and selenium, Se, (number 34) have such similar chemical properties because ________.

their outermost shells contain the same number of electrons

If a neutral element has the following chemical notation, how many electrons does it have? carbon-13

6

The isotope lithium-7 has a mass of 7.0160 atomic mass units, and the isotope lithium-6 has a mass of 6.0151 atomic mass units. Given the information that 92.58 percent of all lithium atoms found in nature are lithium-7 and 7.42 percent are lithium-6, calculate the atomic mass of lithium, Li (atomic number 3).

6.942 amu

What is the main difference between a conceptual model and a physical model?

A physical model represents the shape and form while a conceptual model describes how a system behaves.

An atom absorbs or emits only particular frequencies of light. White light bends into a glass prism and separates into a rainbow of colors. In which of these two scenarios does the electromagnetic radiation behave as a wave? As a particle?

Absorption of light shows particle behavior while bending of light shows wave behavior.

How is it possible for an atom to emit visible light even though the atom is smaller than the wavelength of visible light?

Any charged object, including the smallest atom, generates electromagnetic waves as it vibrates, which we observe in the visible spectrum of an element.

Which of the following atoms is the largest?

Be Mg Sr Ca Correct! *Ba*

How can a hydrogen atom, which has only one electron, have so many spectral lines?

Because there is more than one energy level in a hydrogen atom.

Which of the above has the highest frequency?

C; little, shortest, and very tight together.

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

D; Empty circle

Which of the above has the highest wavelength?

E; Tall, very spread apart.

What was Niels Bohr's explanation for the observation of atomic spectra?

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

What is a probability cloud?

It is a three-dimensional map of the likelihood of finding something within a given area.

Which of the following is a property of light?

Its energy comes in packets of uniform size. Correct! *all of the above* none of the above It is a wave. It is a particle.

Which of the following statements best describes electromagnetic radiation?

Light waves are oscillations of electric and magnetic fields.

List the following elements in order of increasing ionization energy: Tin, Sn; Lead, Pb; Phosphorus, P; Arsenic, As.

Pb < Sn < As < P

Which of the following experiments helped to determine the charge of an electron and (indirectly) its mass?

R. Millikan's oil drop experiments

An electron in the outermost shell of which group 1 element experiences the greatest effective nuclear charge?

Sodium, Na