a set of symbols used to describe the elements within a substance

example: Table salt is composed of two elements sodium and chlorine.

the one- or two-letter representation of an element; symbols are often derived from

example formulas, and equations example H1

A pure substance that is formed when two or more different elements combine; can usually be. separated into component elements by chemical reaction

example: water is a chemical compound contains one part oxygen 2 parts hydrogen

a pure substance that cannot be broken down into simpler substances by chemical reactions

example oxygen, gas, gold

two or more atoms joined together

example a drop of water, two atoms joined together like water and hydrogen

a large molecule that is made of small molecules that are arranged in a repeating structure

example: cellulose is ________of glucose, Plastic poly vinyl.

• Particle interactions are involved in the changes that take place in a burning match. ______occurred and gave way to chemical changes.  In a chemical reaction, something new is being made.

• What occurred?

• Atoms are the smallest part of matter and are made up of protons ____________________?

• Protons and neutrons are in the ________and electrons orbit the ______.

Each _______ is made up of the same type of atoms and has specific properties. 

A ________ is made up of two or more different elements chemically combined to make something new (ex. NaCL, H2O). Be aware that H2 or O2 are not compounds; they are elements.

A molecule is ________joined together. It is the smallest particle of a pure substance. (examples - O2 and CO2 are molecules).  That said, all compounds are molecules, but not all molecules are compounds. That is because a molecule can be made up of two atoms of the same kind, as when two oxygen atoms bind together to make an oxygen molecule. However, all compounds are made up of two or more different types of atoms.

• We compared and contrasted a pure _________. (Ex. a glass of pure water vs. a glass of salt water). The water alone is a pure substance. The salt water is a mixture. which are different types of molecules mixed together. Borax in water to make the crystals is another mixture that we will use to make ornaments.

• We learned that humans and other living things are made up of mainly ____________These elements are also found in our atmosphere and there is a continuous interchange or cycling of these elements between the air and living things all the time. 

• We looked at different substances under the microscope such as carbon and salt and saw they had different structures and properties.We discussed_____________________

• Even elements can be structured differently. For example,  carbon comes in different forms even though it is one type of element. It can be graphite (in a pencil)  or compressed into a diamond.

• The ________ helps chemists predict how atoms will combine and use that information to create new molecules/compounds for different uses.  

• The periodic table is arranged by atomic number. The atomic number is the number of protons and that is different for each element on the table (Hydrogen is 1, Helium is 2, Lithium is 3, etc). The atoms should have the same number of electrons as protons. We determine the number of neutrons in an atom___________________

• The __________ (electrons in outer orbit) will determine reactivity. The first orbit is full at 2 and the next orbit is full at 8. The remaining orbits can hold different amounts but eight is still enough to fill it and would make it “happy.” Those atoms that do not have full outer orbits will try to bond with other atoms so they can fill them.

• The table is also arranged into __________________.

• Periods are arranged horizontally with the atomic number getting higher as you move from left to right. There are 7 periods. The periods tell us how many orbits each atom has. (ex. Lithium is in period 2 so it has 2 orbits)

• Groups are arranged vertically and all the elements in each group or family have similar properties. For example, all the elements in group 18 are noble gasses and do not bond with other atoms because their outer shells of electrons are full.  Group 17 are Halogens and they have seven electrons and are quite reactive. There are_____________

• Most of the elements are metals. _____________________________________. Some of the ones on the "stairs" are metalloids and have some non-metal and metal properties. 

• Except for group 18, the elements on the right side of the table have a _______ attraction (force) to other elements than those on the left side, 

H2 - covalent bond

H2O - polar covalent bond

• shares them unevenly - Oxygen has stronger attractive force and the electrons revolve around it more than the hydrogen atoms and make oxygen slightly negative and hydrogens slightly positive.

• _---

  ________ transfers its outer electron to Chlorine which needs one electron. This makes sodium a positive ion because it now has 11 protons and 10 electrons.

• Chlorine becomes a negative ion because it has ________________.

• The sodium and chlorine ions are attracted to each other because of their opposite changes.  They make sodium chloride. It is a totally different substance!

NaCl (salt) -

To get a full outer shell or orbit of electrons, elements can bond with each other by sharing electrons with each other or giving them away (transferring).

Review diagrams of each in notebooks.

Examples:

Everything in our world is made up of tiny particles called?

Each element has a symbol made of two or more letters,_______

Every element and molecule has a ________to show how many atoms.

sodium chloride is difficult to reverse its________

water is a_______made of two elements.

All matter is made up of ______

An element has one type of_______

Each element has its own name a_____

atoms can join together to form_____

Elements can combine a chemical reaction and form a________

When elements react together they either gain or lose electrons from their?

Elements combine to form chemicals called?

sodium and chlorine elements, when the sodium electron moves to the chlorine atom they react to form an?

When two non mental react together it is a ______

wha is it when water is made up of one oxygen atom and two hydrogen atoms?

Polar means electrons are not shared_______

Water oxygen acts______and hydrogen acts______

This gas is found in the atmosphere and the chemical formula is Co2?

water is made of the elements of hydrogen and oxygen, this is______

How many atoms in water?

what is a large molecule called?

In an atom's center is a nucleus made up of_______

What are the parts of the atom surrounding it? looks like the web picture?

There are ____naturally occurring elements.

With 92 elements how many compounds can be made?