What are these made of?

Elements

Elements

Elements are any pure substance. They are made of only one type of atom. Some examples of elements are gold (Au), calcium (Ca), and oxygen (O).

Gold is a shiny yellow metal.

Did you know that calcium is a metal? It is a very soft metal - so soft you can cut it with a butter knife! Your body needs calcium to have strong, healthy bones.

It’s kind of hard to see oxygen because it is an invisible gas. You’re breathing it in right now as you read this!

• There are 92 natural elements that exist on the Earth.

• Scientist have been able to make about 20 more elements.

• Everything on Earth is made of elements. • The smallest piece of an element is an atom.

Elements

goldsilver

heliumoxygen

mercury

hydrogen

sodium

nitrogen

niobium

neodymium

chlorine

carbon

Examples of Elements

• All of the elements can be found on the Periodic Table.

• The Periodic Table is organized based on the mass (kind of like weight) of each element.

The Periodic Table

The Periodic Table

• Here is what an element on the periodic table looks like close up:

The Periodic Table

C6

Carbon

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Chemical Symbol is an abbreviation for the element. It can be 1 or 2 letters.

Atomic Number is the number of the element on the periodic table and tells you how many protons the element has.

Phase of matter the element is at room temperature.

Atomic Weight is the mass of the atom. It is the number of protons plus neutrons.

Element’s Name

• A few more things:◦ The atomic number tells you the number of

protons. The number of protons also equals the number of electrons.

◦ To find the number of neutrons, take the atomic weight and subtract the atomic number.

The Periodic Table

2 electrons fit in the first circle around the nucleus.

8 electrons fit in the next two circles.

The nucleus contains the protons and neutrons.

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Isotopes - are the same element with the same number of protons, but has a different number of neutrons.

The atomic mass of an is the average mass of the elements isotopes, weighted according to the abundance of each isotope.

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Remember that ions are atoms that have lost or gained an electron and no longer is neutral.

Positive ions have lost one or more electrons. Making the over all charge of the atom positive.

Negative ions have gained one or more electrons. Making the overall charge of the atom negative.

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Nuclear decay - this is a process by which an unstable atomic nucleus by changing into a more stable nucleus by emitting radiation.

There are three different types of radiation.

Alpha Decay

Beta Decay

Gamma Decay

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Alpha decay is made up so two protons and two neutrons. When the atom releases the alpha particle the atomic number decrease by two.

Uses - smoke detector batteries,help in treatment of cancer, help reduce static electricity, and used in batteries in human pacemakers.

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Beta Decay - happens when a neutron in an atom changes into a proton, and releases a high-energy electron called a beta particle. In response the atomic number has increased by one because it has gained an proton.

Uses - some cancer treatments, plastic industry, and tracers.

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Gamma Decay - this type of decay does not have particles, but does have a lot of energy. Because they don't release particles it does not change the element.

Uses - cancer treatment, x-Rays, food irradiation.

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