Chapter 10 - Atoms Flashcards Preview

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Flashcards in Chapter 10 - Atoms Deck (45)
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1

All matter consists of what?

Atoms

2

Where are protons and neutrons found?

In the nucleus

3

Where are electrons found?

Orbiting the nucleus in electron clouds

4

State the charge of each subatomic particle: Proton, Neutron, Electron

Proton: Positive (+)
Neutron: No charge (0)
Electron: Negative (-)

5

The atomic number is equal to the number of _____ in an atom

protons

6

In an element that has no overall charge, the atomic number also helps you identify what? Why?

The number of electrons; the number of protons (+) and electrons (-) must equal to create no overall charge in the element. So if the atomic number is 5 in an element (5 protons), then the element also has 5 electrons.

7

What is the mass number?

The sum of the numbers of protons and neutrons in the nucleus of an atom.

8

What is the atomic mass of an element?

The number that averages all of the masses of isotopes of an element together.

9

If O-10 takes up 50% of all Oxygen (O) atoms in nature and O-4 takes up 50% of all Oxygen (O) atoms in nature, than what is the atomic mass for oxygen?

10 * 50% = 5
4 * 50%. = 2
___________+__
7 atomic mass units (amu)

10

The number after the hyphen in an atom (H-12) is the atom's what?

Mass number

11

How do you find the number of neutrons in an element?

Subtract the atomic number(# of protons) by the atomic number

12

Element:Atomic Mass :: Atom:_____

Mass number

13

What defines an element(no other element has the same ____)?

Its atomic number

14

Two atoms have the same atomic number but a different number of neutrons(and therefore a different mass number). What are theses elements called?

Isotopes

15

The electron is a lot (larger, smaller) than a proton or neutron

Smaller

16

If an atom has more protons than electrons, then it is what?

A positively charged ion

17

Describe gravitational force.

All objects attract each other. The larger the mass and the greater the distance between objects, the stronger the gravitational force.

18

Describe electromagnetic force.

Objects with alike charges repel and objects with different charges attract.

19

Describe strong force.

The close distance between the neutrons and protons in the nucleus of an atom causes strong force and keeps the nucleus together. Without the neutrons, there would be no buffer between the protons, causing them to repel each other.

20

Describe weak force.

In some unstable atoms, neutrons have the ability to change electromagnetic charges; it can turn into a proton or electron. Weak force plays a key role in radioactive elements

21

Who thought that you could keep cutting a particle infinitely?

Aristotle

22

Who thought that you would end up with a particle that couldn't be divided?

Democritus

23

Who experimented with different substances and developed an atomic theory?

John Dalton

24

Who found that atoms could be divided into further parts and discovered the electron of the atom? He also created the plum-pudding model.

J.J. Thomson

25

Who used a gold-foil experiment to discover the small, dense nucleus of the atom?

Ernest Rutherford

26

Atoms consist mostly of _____

Empty space?

27

Who discovered that electrons can jump between certain paths, or energy levels?

Niels Bohr

28

What are electron clouds?

Regions around the nucleus where electrons are likely to be found.

29

Up to how many electrons can each energy level hold?

1st: 2
2nd: 8
3rd: 18

30

Is it possible to have 1 electron on the first energy level, and 4 on the 2nd? Why or why not?

No; the 1st energy level must reach its maximum capacity (2)before electrons can go on the 2nd energy level.