ATOMS and THE PERIODIC TABLE

NAME _______________________ PER_____ DUE DATE _________________ MAIL BOX________

BRING COMPLETED REVIEW PACKET COMPLETE TO THE EXAM, THE DAY OF EXAM - RECEIVE 1 BONUS PT ON EXAM

Check your work, find answer key on website

1. A unit of mass used to express atomic and molecular weights. One proton or

neutron equals one mass unit.

2. This is the center of atom. Most of the mass of the atom is here.

3. These are positively charged particles. They define an atom’s identity.

4. These are negatively charged particles. They define an atom’s reactivity.

5. These particles add to an atom’s mass.

6. The basic unit of a chemical element.

7. The mass of an atom of a chemical element expressed in atomic mass units. It is

approximately equivalent to the number of protons and neutrons in the atom (the

mass number) or to the average number. This why it is typically expressed with a

decimal.

8. Each of two or more forms of the same element that contain equal numbers of

protons but different numbers of neutrons in their nuclei, and hence differ in relative

atomic mass; in particular, a radioactive form of an element.

9. 10.

Matching

____ ATOM

____ATOMIC MASS

____ NUCLEUS

____ ISOTOPES

____ AMU

____ PROTONS

____ NEUTRONS

____ URANIUM

____ ELECTRONS

____ HYDROGEN

Read:

An atom is made of three basic particles; neutrons, protons and electrons. These are building blocks

of atoms are comprised of particles even smaller still such as quarks, leptons and neutrinos. Protons

have a positive charge and neutrons a neutral charge while together they make up the nucleus of an

atom. Varying numbers of protons (atomic number) give us the 94 or so naturally occurring elements

on earth. Varying numbers of neutrons simply effect atomic mass and give rise to different isotopes of

the same element. Atomic mass is the combined mass of both neutrons and protons. The electrons

which have a negative charge spin in

orbits around the nucleus. Each atom

has an equal number of protons and

electrons. Because, the negative

charge of the electrons balances the

positive charge of the protons, making

atoms typically neutral. Can you the

parts of this atom here? →

Atomic Theorems  commit to memory, commit to memory

1. atomic number = proton count

2. proton count = electron count

3. atomic mass (minus) atomic number = neutron count

4. atomic mass = protons + neutrons

5. neutrons do not equal atomic mass

6. neutrons do not = electron count

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7. Periods equal number of electron shells around nucleus

8. Groups equal number of valence electrons

7 & 8 Apply only to → (Alkali, Alkaline, BCNO Family, Nonmetals, Halogens and Noble Gases (not Transition Metals)

Using the Atomic

Theorems and a

Periodic Table these

should be easy

→ Fill in blank →

Using a Periodic Table

ID these atoms

→ Label→

Identify each of the following. Which is which?

Iodine - Chlorine - Bromine – Florine

If you’re stuck count the shells &/or count valence electrons.

SCALE of ATOMS : 1mm = 1000 micronmeters (um)

1 micrometer = 1000 nanometers (nm) no ruler? call it →→ 40 mm

Measure the atom’s electron shell diameter.

What is the scale of this model if this atom’s valence electron shell

is 0.2 nanometers in diameter.

1. Measure the atom’s diameter, WRITE here→ _____mm = 0.2nm

2. Set up a proportion & report what 1mm equals to scale in the box.

Think about it…. I telling you the whole atom equals 0.2nanomters but what about the nuclues in this model or

the distance between on electron shel and another???

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MODELS OF THE ATOM THROUGHOUT HISTORY

Fill in the physicists’ name for each of the below passages. (Hint see scientist names above)

_____________ was able to arrive at his model of the atom through careful observations using a

cathode ray tube. He called it plum pudding; positive pudding with negative electrons scattered

throughout.

A. Dalton B. Thomson C. Rutherford D. Bohr

_____________ utilized radioactive decaying material to fire alpha particles at a sheet of gold to

arrive at his model. Most of the alpha particles went right through. A few smashed into a densely

packed positive nucleus.

A. Dalton B. Thomson C. Rutherford D. Bohr

_____________ model paved the way for the present day Modern Model of the atom. He and others

proposed electron energy levels or quanta to explain the structure of the atom.

A. Dalton B. Thomson C. Rutherford D. Bohr

The Atomic Models - What were the major discoveries that each of the following

atomic models represented in its day?

MATCHING

WRITE LETTERS A-E ON THE LINES BELOW

Refer back to classwork, lab and notes for help.

______ The nucleus is discovered. The atom is found to be

mostly empty space. The nucleus is discovered to be an

extremely small dense and positively charged region.

______ The atom is found to be divisible, not indivisible as

had long been thought. The electron is identified as a discrete

part of the atom with a negative charge. The model is

described as “plum pudding”.

______ The remaining unexplained mass of the atom is

explained with the discovery of the neutron.

______ For the first time, specific elements are identified by

atomic mass - hydrogen, oxygen, nitrogen, sulfur, phosphorus

and carbon. Atomic structure still however unknown.

______ Quantum theory is adopted to explain electron levels

and the structure of the atom. The proton also becomes a

well-defined particle during this time period.

John Dalton

----------------

J.J. Thomson

-----------------

Ernest Rutherford

-------------------

Niels Bohr

-------------------

James C

hadwick

1766

-1844

Late 1800s

1871

-1937

Early 1900s

1921

-1935

A

B

C

D

E

The Atomic Models - What were the major discoveries that each of the following

atomic models represented in its day?

Can you label 2-3 keys features in each diagram.

Dalton identifies for the first time specific elements by

atomic mass - hydrogen, oxygen, nitrogen, sulfur,

phosphorus and carbon. Atomic structure still however

unknown.

The nucleus is discovered. The atom is found to be

mostly empty space. The nucleus is discovered to be an

extremely small dense and positively charged region.

Rutherford

The atom is found to be divisible, not indivisible as had

long been thought. Thomson “Father of the Atom”

identifies the electron as a discrete part of the atom

with a negative charge.

Quantum theory is adopted to explain electron levels and

the structure of the atom. Niels Bohr provides

experimental evidence. The proton also becomes a well-

defined particle.

The remaining unexplained mass of the

atom is explained with the discovery of

the neutron by Chadwick.

John Dalton

----------------

J.J. Thomson

-----------------

Ernest Rutherford

-------------------

Niels Bohr

-------------------

James Chadwick

1766

-1844

Late 1800s

1871

-1937

Early 1900s

1921

-1935

What are the names of each the following groups: 1-8

Read over Groups

and their

descriptions

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