Ch. 4 Study Guide

Question 0

What was Aristotle’s thought about all substances?

HINT**There are 2

Answer 0

That they were made up of only four elements: fire, earth, water, air.
There is no limit to the number of times that matter could be divided.

Question 1

What is the greek word for “atom”?

Answer 1

Atomos

Question 2

What did Dalton study in his free time? Why?

Answer 2

Gasses; he was interested in predicting the weather

Question 3

What was Dalton’s evidence for the existence of atoms?

Answer 3

When he measured the masses of elements, he noticed that all the compounds had one thing in common: no matter how large or small the sample, the ratio of the masses are always the same.

Question 4

What would be a good representation of Dalton’s theory?

Answer 4

Solid spheres

Question 5

What charges repel and what charges attract?

Answer 5

Like charges repel while opposite charges attract

Question 6

What did Thompson use to learn more about atoms?

Answer 6

An electric current

Question 7

Explain Thompson’s experiments.

Answer 7

He used a tube of sealed gas in his experiments. When the current was on in one of the two tubes, the disks became charged and a glowing beam appeared in the tubes. When the current was on in the other tube, the beam bent towards the positively charged plate (there was no charged plates in the first tube).

Question 8

Describe thompson’s model.

Answer 8

Negative charges were evenly scattered throughout the positively charged atom.

Question 9

What was Thompson’s model called?

Answer 9

Plum pudding model

Question 10

Who discovered alpha particles?

Answer 10

Rutherford

Question 11

What are alpha particles?

Answer 11

Fast-moving particles that have a positive charge

Question 12

Describe the gold-foil experiment.

Answer 12

Rutherford aimed a narrow beam of alpha particles at gold-foil. The screen around the gold was made up a material that produced a flash of light when struck by a fast moving alpha particle. Five serving the flash, one could figure out the path of the alpha particle after he passed through the gold.

Question 13

What did Rutherford conclude from the gold for foil experiment?

Answer 13

The positive charge of an Atom is not evenly spread throughout the Atom

Question 14

According to the weather for model, all of that Adams positive charge is concentrated where?

Answer 14

In the nucleus

Question 15

What are the three subatomic particle’s?

Answer 15

Protons electrons and neutrons

Question 16

What kind of charged as a proton have?

Answer 16

A positive charge

Question 17

Where is the proton found in an atom?

Answer 17

In the nucleus

Question 18

What kind of charge does an electron have?

Answer 18

A negative charge

Question 19

Where is an electronic found in an atom?

Answer 19

In the space outside the nucleus

Question 20

What charge does a neutron have?

Answer 20

A neutral charge

Question 21

Where are neutrons found In an atom?

Answer 21

In the nucleus

Question 22

Which two subatomic particle’s have almost exactly equal masses?

Answer 22

Neutrons and protons

Question 23

What can subatomic particle be distinguished by?

Answer 23

Mass, charge, and location in in atom

Question 24

What number is always the same in any given element?

Answer 24

The atomic number

Question 25

What is the atomic number of an atom?

Answer 25

It is the number of protons in and Atom

Question 26

What is different for every element?

Answer 26

The number of protons, or the atomic number

Question 27

Which two subatomic particles have the same amount of particles in each atom?

Answer 27

Protons and electrons

Question 28

What is the mass number of an Atom?

Answer 28

The sum of the protons and neutrons

Question 29

What is an isotope?

Answer 29

It is atoms of the same element that have different numbers of neutrons a different mass numbers

Question 30

What did Bohr’s model do that Rutherford’s model didn’t?

Answer 30

Focus on the electrons

Question 31

How do electrons move in Bohr’s model?

Answer 31

They move with constant speed and fixed orbits around the nucleus

Question 32

Each electron in an atom has a specific amount of what?

Answer 32

Energy

Question 33

What is an energy level?

Answer 33

The possible energies that electrons in and atom can have

Question 34

And electrons energy level is affected by what?

Answer 34

Whether the atom gains or loses energy

Question 35

An Electron in a high energy level may move up or move down to energy levels?

Answer 35

Down

Question 36

What evidence is there that electrons can move from one energy to another?

Answer 36

Scientist can measure the energy again when electrons absorb energy and move to a higher energy level. They can also measure the energy released when the election returns to a lower energy level

Question 37

What was Bohr’s model correct about?

Answer 37

He was correct in assigning energy levels to electrons

Question 38

What is an electron cloud?

Answer 38

A visual model of the most likely locations for electrons in an atom

Question 39

What do scientists use the electron cloud model for?

Answer 39

Do you describe the possible locations of electrons around the nucleus

Question 40

What is an orbital?

Answer 40

A region of space around the nucleus where electron is likely to be found

Question 41

What is an electron cloud a good approximation of?

Answer 41

How electrons behave in the orbitals

Question 42

What is electron configuration?

Answer 42

It is the arrangement of electrons in the orbitals of an atom

Question 43

What is an electron configuration the most stable?

Answer 43

When the orbitals on the lowest possible energy’s

Question 44

What is ground state?

Answer 44

When all the electrons in an atom have the lowest possible energy

Question 45

What is the excited state?

Answer 45

It is when electrons move to an orbital with a higher energy level

Question 46

What assumption did Aristotle make on atoms?

Answer 46

They were based on four elements: earth, fire, water, air