The Atoms Family

Atoms are the smallest form of elements

Matter

• Anything that has mass and takes up space (has volume)

• Made up of different kinds of atoms

• Includes all things that can be seen, tasted, smelled, or touched

• Does not include heat, sound, or light

In science, anything that has mass and takes up space is called matter

Everything in the universe is made of matter

A really loooooong time ago, the Greeks concluded that matter could be broken down into particles too small to be seen.

They called these particles atoms

So, what’s an atom?

An atom is the smallest piece that matter can be broken down to

Okay, but I’ve never seen an atom . . . Where are they?

Atoms are EVERYWHERE!!

Atoms are in . . .

hair

desks

dirtchocolate cheese

CDs

air

And even underwear

boogers

cars

hot dogs

plants

Pop Quiz Question #1

What are the three states of matter?

A. solid, water, boiling

B. Water, ice, steam

C. Solid, liquid, gas

D. earth, rain, air

What do atoms look like?

There is no "atomic microscope" which would allow one to look inside an atom and say, "Aha! There's 7 blue protons, 6 white neutrons, and 7 red electrons." The way the structure of the atom was devised was through a long series of experiments

Scientists have developed models . . .

Models

• In the case of atoms, scientists use large models to explain something that is very small

• Models of the atom were used to explain data or facts that were gathered experimentally.

• So, these models are also theories

Early Models of the Atom Democritus

• Universe was made of empty space and tiny bits of stuff

• Called these tiny bits of stuff atomos• Atoms could not be divided

Early Models of the Atom Dalton

• All elements are composed of indivisible particles.

• Atoms of the same element are the same• Atoms of different elements are

different. • Compounds consisted of atoms of

different elements combined together

Early Models of the AtomThompson

• Plum pudding model

• Atom made of a positively charged material with the negatively charged electrons scattered through it.

Early Models of the Atom Rutherford

• Mostly empty space• Small, positive nucleus • Contained protons• Negative electrons

scattered around the outside

Early Models of the Atom Bohr

• Electrons move in definite orbits around the nucleus

• Solar system model

Modern Model of the AtomThe electron cloud

• Sometimes called the wave model

• Spherical cloud of varying density

• Varying density shows where an electron is more or less likely to be

Atomic Structure

• Electrons– Size = Tiny, very light particles

– Charge = negative electrical charge (-)

– Location = Move around the outside of the nucleus

– Number = Same as Protons (if atom is neutral)

– Purpose: Does the Work • Bonding

• Chemical Reactions

Atomic Structure• Protons

– Size = Much larger and heavier than electrons– Charge = positive charge (+)– Location = in nucleus of the atom – Number = Same as Atomic Number– Purpose: Keeps the electrons around

Atomic Structure

• Neutrons– Size = Bigger than protons– Charge = no electrical charge (0)– Location = nucleus of the atom – Number = Atomic Mass – Atomic Number– Purpose: Keeps the protons together

Protons and NeutronsProtons and neutrons are responsible for most of

the mass of an atom.

If the proton and neutron each had the mass of a hippo, the electron would have less mass than an owl.

Protons and neutrons are located in the of the atom

nucleus

Pop Quiz Question #2

Do neutrons have a charge?

A. Yes, they’re positive.

B. Yes, they’re negative.

C. Yes, they’re neutral.

D. No, they’re neutral.

Pop Quiz Question #3

What are the three parts of an atom?

A. Solid, liquid, gas

B. Proton, neutron, electron

C. Atom, cell, virus

D. Positive, negative, neutral

Pop Quiz Question #4

Where are protons and neutrons located in the atom?

A. The left

B. The right

C. Nucleus Arcade

D. Nucleus

ElectronsElectrons travel really fast around the nucleus in

electron orbits or shells

Only electrons are located on the first shell, can fit onto the second shell, fit onto the third shell, and fit onto the fourth shell.

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32

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Bohr’s Model of the Atom

electronproton

neutron

shell

Electron Cloud Model

protonelectron

cloud

Elements

An is any piece of matter that consists of only atom.

elementone

There are over 100 elements known to man

Each element has a name and a symbol

Describing Atoms

Each element is identified by its atomic number

The atomic number tells how many are in the nucleus and how many are in the shells

protonselectrons

The total number of protons and neutrons in the nucleus is called the atomic mass number

A neutral atom has the same amount of protons and electrons.

Atomic Math

To determine the amount of neutrons for each element, the from the

subtract atomic numberatomic mass number

How many protons does zinc have?

How many electrons does zinc have

How many neutrons does zinc have?

30

30

35

Pop Quiz Question #5

What information does the atomic number provide?

A. The number of protons and electrons

B. The number of protons and neutrons

C. The number of neutrons and electrons

D. Only the number of protons

Pop Quiz Question #6

An atom is stable when there are the same number of protons as electrons. What would be the charge of an oxygen atom that “lost” two electrons?

A. Positive

B. Negative

C. Neutral

Ions

• An atom that carries an electrical charge is called an ion

• Cation– If the atom loses electrons, the atom becomes positively

charged (because the number of positively charged protons will be more the number of electrons)

• Anion– If an atom gains electrons, the atom becomes negatively

charged (more negative charges than positive charges)

Ions• The number of protons does not change in an

ion

• The number of neutrons does not change in an ions

• So, both the atomic number and the atomic mass remain the same.

IonsSodium has lost an electron. Now it has one more proton than electron.

One more proton means one more positive charge.

This makes the total charge of the atom POSITIVE.

Chlorine has gained an electron. Now it has one less proton than electron.

One less proton means one less positive charge.

This makes the total charge of the atom NEGATIVE.

Isotopes

• The number of protons for a given atom never changes.

• The number of neutrons can change. 

• Atoms with different numbers of neutrons are called isotopes

Drawing Isotopes

How to Write an isotope

• Name of element – Mass Number (Protons + Neutrons) Hydrogen – 1 (has one particle in the nucleus

*the one particle in the nucleus is a proton Hydrogen – 2 (has 2 particles in the nucleus)

*Subtract the atomic number from the new atomic mass to get the new number of neutrons)

Hydrogen – 3 (has three particles in the nucleus)

*Only one particle is a proton, the others must be nutrons)

Pop Quiz Question # 7

How would you write an isotope for carbon that has 2 extra neutrons?

A. Carbon-2

B. Carbon-12

C. Carbon-14

D. Carbon-16