Atom Structure

• Electron- The electron is a negatively charged subatomic particle and is found outside of the nucleus.

• Proton- The proton is a subatomic particle that is positively charge and is found in the nucleus of the atom.

• Neutron- The neutron is the subatomic particle that is neutral in charges, doesn't have an electric charge and is also found in the nucleus of an atom.

• Nucleus- The nucleus of the atom is consisted of the protons and neutrons and are located right in the center of the atom where both, protons and electrons are stuck together.

Periodic Table

Introduction

What does the periodic table show? ? ? The periodic table is a chart, created by famous Russian scientist Dmitri Mendeleev. It shows all the elements that excist such as oxygen,It has specific facts about each of them such as the ones listed below :

Atomic Number

Mass Number

Number of Protons in

Atom

Number of Electrons in Atom

Chemical Symbol

Number of Neutrons in Atom

Metal / Nonmetal

Chemical Activity

Oxidation Number

Electron Energy Levels

Electron Energy Sublevels

Orbitals within Sublevels

Electron Configuration

Families of Elements

Natural / Manmade

Physical State at Room Temperature

Basic Structure

The periodic table sometimes shows whether it is artificially made or whether it is radioactive or not. It is divided in metallic or non-metallic gases. It is also divided into other groups like halogen gas, noble gases, alkali metals and alkaline-earth elements. These groups go under the transition metals and most active metals. Periods in a periodic table are horizontal rows and are numbered from 1 to 7. Also, in a periodic table, elements with similar properties are put under each other in the vertical columns or groups. The following are a description of each of the 4 groups:

Alkali metals: These have one valence electron. They are part of family 1. Alkaline earth metals: They have 2 valence electrons. They are categorized as family 2. Halogen gases: These have 7 valence electrons and fall in family 17. Noble gases: Member of family 18 and has 8 valence electrons. It is highly unreactive. These are either in metals (good conductor of heat and electricity, shiny, high melting point, ductile and malleable, and tends to lose electrons) or non-metals (opposite characteristics of metal).

Physical Properties of Metals

All metals have a different characteristic, but all have general properties. Metals are usually determined by their hardness. They can resist surface deformation or abrasion. They are very shiny. They have very tensile strength, meaning that it can resist itself from breaking. Metals have elasticity, or the ability to return to it's original shape after deformation. It also has malleability. This means that metals can be hammered into shape. It can resist repeated stresses or fatigue resistance. Also it can undergo deformation without breaking or, in other words, it is ductile. Also they are very good conductors of electricity and heat.

Chemical Properties of Metals

Most metals have positive valences. This means that, during a reaction, they tend to give away electrons to those they react with. Also, metals have low combining power. So, when they react and mix, they easily lose electrons.

Physical Properties of Non-Metals

Nonmetals are the total opposite of metals. They can break easily when you try to deform it. They are more prone to scratches and can't hold repeated stresses. It can not conduct heat and electricity very well. They have low melting points compared to the metals. They can not be hammered into thin sheets or be turned into wires. They are usually dull.

Chemical Properties of Non-Metals

Non-metals have negative valences unlike metals. They either react mildly (carbon group, nitrogen group and oxygen group) or they are non-reactive (noble gases). Non-metals also tend to gain more electrons during a reaction.

Description of Common Elements

Oxygen is one of the most important element for us humans. It gives life to all living organisms.Oxygen in the air. 50% of the earth's crust is made up of oxygen. That means that no matter what you pick up,or dig up from the ground, there's a good chance that one half of it is made up of oxygen. Over half of the Earth is covered with water. Mixed in that water is oxygen. The same way we breathe the oxygen in the air, fish breathe the oxygen in the water. It's symbol is O and has an atomic number of 8.The atomic mass of this element is 15.9994 atomic mass unit (amu) and it's melting point is -218.4 C and the boiling point gets up to be -183.0 C. It consists of 8 protons, 8 electrons and 8 neutrons.It's classified as a non-metal element and has a Cubic crystal structure. It is a colorless element and has a density @ 293K:1.429 g/cm3.

Nitrogen is also a real important element in our lives. It is the necessary element for plants. Without it, plants would not live. Nitrogen is like oxygen to us as nitrogen is to plants. Nitrogen is used in the process to make steel. Many elements are used to make steel. It is not an easy thing to do. Scientists use nitrogen in many difficult processes. Nitrogen is used as a refrigerant. When it is in a liquid form, nitrogen is very cold. Scientists use that cold nitrogen to keep things frozen. Nitrogen is used to refine oil. Scientists get oil out of the ground, but it can't be made into gasoline without nitrogen. The symbol is N and has an atomic number of 7 and an atomic mass of 14.00674 amu. It has 7 protons, neutrons, and electrons. It is classified as a Non-Metal elementand has a hexagonal structure. It has density @ 293K: 1.2506.

Hydrogen is a non-metal element and is the simplest and lightest elements ever. Hydrogen is in all plants. There are sugars all throughout plants and there is hydrogen in sugar. That's why animals eat plants, for the sugar, and for the energy. Hydrogen is used in something called cryogenics. Cryogenics is a process where scientists freeze things. When hydrogen is in a liquid form, it is very, very cold. Scientists use this cold hydrogen to freeze things very quickly. It is the element of water and it's symbol is H. It is usually colorless and odorless and it has an atomic weight of 1.0079 amu and the atomic number is 1. It has 1 proton and 1 electron. It has a hexagonal crystal structura and has a density @ 293 K: 0.08988 g/cm3.

Carbon is a non-metallic element that is found in every living thing.Gasoline is made up of oil and oil is created from plants which died millions of years ago. You know there is carbon in plants, so there is carbon in oil and gasoline. Everything that is plastic, has carbon in it. We just talked about gasoline. Like gasoline, plastic things are made from oil. That means carbon is the most important element plastic. It has symbol which is C and its atomic number is 6. The carbon's atomic mass is 12.0107 amu. Has 6 number of protons, electrons, and neutrons and is classified in the periodic table as Non-Metal and has a crystal structure as hexagonal. Carbon may be black and has a density @ 293 K: 2.62 g/cm3.

Sodium is an alkali metal element. Sodium is used to make glass. You know that silicon makes up most of glass, but in the process of making glass, sodium is often used.Sodium is a very important element in fertilizers. Farmers use a lot of fertilizer to make sure their crops grow well. You parents might even use fertilizers in their garden. It has a symbol which is Na and its' atomic number is 11. The atomic mass of sodium is 22.98977 amu. It has 11 protons, electrons, and has 12 neutrons. It has a cubic crystal structure and it is a silvery colored element. It has a density @ 293 K: 0.971 g/cm3.

Other Web Sites on Chemistry

Elements
Periodic Table
Atomic Structure
Chemicals

This web page was created by Andres Pacheco.

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