# Activity & lab notes to model Atoms, Elements, & Compounds

## Concepts

• Nuts and Bolts can be used to make a model of compounds.
• Compounds are chemically bonded elements.

## Activity 1

Get the following materials

• 1 long bolt
• 1 short bolt
• 2 hex nuts
• 2 square nuts

Place both kinds of nut atoms and bolt atoms in 4 separate piles on your desk.

Short bolt      Hex nut       Square nut       Long bolt

How many different kinds of atoms do these nuts and bolts represent?

If each kind of atom makes up a different element, How many different elements are represented?

In order to make a compound, at least two atoms have to combine, or be bonded together.

For example, a short bolt atom may be combined (bonded) to a square nut atom.

A sketch representing this combination could be:

Assuming that Bo is a symbol for a short bolt atom and Sq a symbol for a square nut atom, then the above combination could be described by the following symbol BoSq.

What would the following symbols represent? BoSq2

What does the subscript 2 mean?

Make a sketch representing this combination.

The symbol for a long bolt atom and a hex nut atom are shown below.

Bl               Hx

If a long bolt atom and hex nut atom were combined , the what would the shorthand symbol be?

• Use 1 long bolt, 1 short bolt, one square nut and one hex nut to determine how many other different combinations (compounds) can be made.
• Once a combination is made (1) draw it and (2) write its symbol in Data Table #1.
• Then take the combination apart and try again.
• Those already constructed have been entered in the table.
• Darken the heads of long bolts in your sketch.This will serve to distinguish them from short ones.
Data Table #1
Picture of Combination Shorthand Symbol

BoSq

BlHx

How many different compounds did you make?

To be counted as a different compound the combination has to have a different formula.

How do your combinations compare to another teams?

The set of symbols in the table above are also called formulas.

A symbol represents one kind of atom, but, a formula represents a combination of more than one kind of atom. It tells the number and kinds of bolts and nuts (atoms) held (bonded) together.

What is the formula for the combination of two short bolts and two square nuts?

What do the subscripts mean?

Using long bolts and hex nuts, make a compound that has the formula
Bl2Hx2
and sketch it.

Could it be made in a different way?

If so, sketch it.

What information about a combination is lost by just using the symbol?

Sketch the number of different ways two long bolts can be combined with four square nuts in the table below and write a formula for each. All four nuts have to be used each time.

Data Table #2
Picture of Combination Formula

Shorthand symbols could be used to describe how to form a combination (compound). For example, a combination of two long bolts and two hex nuts are threaded together.

This could be described in words

A ( _______________________) is made from

TWO LONG BOLTS ( ______________)

PLUS TWO HEX NUTS ( ______________)

TWO-BOLT-TWO-NUT COMBINATION (______________)

or pictures

or by using symbols

2B l + 2Hx   ->  Bl2 Hx2

What does the Bl and Hx to the left of the arrow represent?

What does the arrow mean?

What does the formula, Bl2 Hx2 to the right of the arrow mean?

What do the prefix numbers represent on the left side of arrow?

What about the subscript numbers to the right of the arrow?

### Create your own interaction with bolts and nuts:

Interaction 1

Draw a Diagram

Write a word description of this interaction.

Now, write a description using symbols.

Interaction 2

Draw a Diagram

Write a word description of this interaction.

Now, write a description using symbols.

### How does this relate to the chemisty?

There are millions of different substances in the universe.

However, scientists believe that everything on the earth and the stars are made of various combinations of only about 100 basic substances called elements.

They can be explored in the electronic periodic table of elements supported by the Los Alamos national laboratory.

Some Elements and symbols
Name Symbol Name Symbol Name Symbol
Aluminum Al Iodine I Oxygen O
Calcium Ca Iron Fe Potassium K
Carbon C Lead Pb Silver Ag
Chlorine CI Magnesium Mg Sodium     Na
Copper Cu Mercury Hg Sulfur S
Helium He Nitrogen N Zinc Zn
Hydrogen H

The penny is made of copper.

What is its symbol?

Many beverage cans are made of aluminum.

What is its symbol?

The oxygen found in air is made of two atoms.

Write its formula.

The nitrogen in air is also made of two atoms.

What would its formula be?

When atoms of elements combine, compounds are formed.

A compound is identified by two things:

1. The kinds of atoms in it and
2. The number of each kind of atom.

The formula for the compound water is H2O.

What atoms are found in water?

How many of each kind of atom are there?

Complete the table below by adding the missing information.

Some substances & what they are made of!
Substance Formula kind of atom Number of each Atoms
Water H2O H 2
O 1
Table Salt NaCl Na
Cl
Dry Cleaning Fluid CC14
Sugar C12H22O11

Ammonia NH3

Baking Soda NaHCO3

Rust FeO

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