Chapter 4 test

Question 1

State the law of definite proportions in your own words.

Answer 1

Any sample of a compound always has the same composition.

Question 2

State the law of conservation of mass in your own words.

Answer 2

The mass of the products will equal the mass of the reactants in a chemical reaction.

Question 3

Which of Dalton’s four principles are no longer considered correct

Answer 3

The first two. Atoms can be broken down into protons, neutrons and electrons. And there are different isotopes of the same element.

Question 4

What unit would you label an average atomic mass with?

Answer 4

amu

Question 5

Sketch a diagram of Thomson’s cathode ray experiment. Label all important parts.

Answer 5

Question 6

Explain what important conclusions Thomson drew from this experiment.

Answer 6

The beam was made of particles that had mass (he knew this because they could move a paddle wheel) and had a charge (because they could be bent by a magnet). The charge was negative because they moved towards a positive plate and came from the negative side of the power source.

Question 7

What subatomic particle did Thomson discover?

Answer 7

Electrons

Question 8

Sketch a diagram of Rutherford’s cathode ray experiment. Label all important parts.

Answer 8

Question 9

Explain what important conclusions Rutherford drew from this experiment.

Answer 9

Most of the mass of the atom is concentrated in the nucleus, which is positive. He knew this because most particles passed through without changing direction, but a few were deflected or bounced back.

Question 10

What part of the atom did Rutherford discover?

Answer 10

The nucleus

Question 11

What type of spectrum did Neils Bohr study

Answer 11

Line emission spectra

Question 12

What important part of the atom did Bohr discover?

Answer 12

Energy levels

Question 13

What is it called when all of the electrons in an atom are in their lowest possible state?

Answer 13

Ground state

Question 14

What is it called when electrons move to a higher energy state than in question #20?

Answer 14

Excited state

Question 15

What is an orbital? How many electrons can an orbital hold?

Answer 15

The 3-dimensional shape that describes where electrons will probably be found. 2 electrons

Question 16

Orbital letter shape(s) groups of s p d f

Answer 16

Orbital letter shape(s) groups of s sphere 1 p 2 lobes 3 d [four with 4 lobes, 5 and one with 2 lobes and a donut] f don’t need to know 7

Question 17

Energy level orbital types it can contain max. # of orbitals max. # of electrons 1-7

Answer 17

Energy level orbital types it can contain max. # of orbitals max. # of electrons 1 s 1 2 2 s, p 4 8 3 s, p, d 9 18 4 s, p, d, f 16 32 5 s, p, d, f 16 32 6 s, p, d, f 16 32 7 s, p, d, f 16 32

Question 18

State the Pauli exclusion principle and explain how it applies to orbital diagrams.

Answer 18

An atomic orbital may describe at most 2 electrons, and they must have opposite spins. In an orbital diagram, a box can have no more than two arrows, and one must point up and one must point down.

Question 19

State the Aufbau principle and explain how it applies to orbital diagrams

Answer 19

Electrons occupy orbitals of the lowest energy first. Fill orbital diagrams starting at the bottom.

Question 20

State Hund’s rule and explain how it applies to orbital diagrams.

Answer 20

Electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible. In an orbital diagram, follow the bus seat rule.