WORD LIST 2 -SCIENCE

How many Amu's in one gram?

6 X 10 = 600, 000,000,000,000,000,000,000

Element

A substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number. Elements are pure substances. When the subatomic particles of an element are separated from its atom, it no longer retains the properties of that element.

Matter

All matter is composed of atoms and groups of atoms bonded together, called MOLECULES

Amu Unit

Amu stands for atomic mass unit and is used to indicate mass on an atomic or molecular scale

Ion

An atom or molecule which has a negative or positive charge because the number of electrons does not equal the number of protons.

What makes an element reactive?

An incomplete valance electron level. All atoms (except hydrogen) want to have 8 electrons in their very outermost energy level (this is called the rule of octet) Atoms bond until the level is complete. Atoms with few valence electrons lose them during bonding. Atoms with 6, 7, or 8 valence electrons gain electrons during bonding.

Carbon Family "the basis of life"

Carbon atoms have 4 valence electrons It includes a non-metal (carbon), metalloids, and metals. Carbon is called "basis of life". There is an entire branch of chemistry devoted to carbon compounds called organic chemistry.

Compound

Compounds are substances that are made from more than one type of atom bonded together. Two or more elements that are chemically combined. Compounds can only be separated by chemical means. When hydrogen and oxygen are bond, they make the compound WATER

Example of a family

Elements of the same family have similar but not identified properties. For example lithium (Li), Sodium (Na), pottassium (K) are all soft, white, shiny metals.

Law of Conservation of Mass

Established in 1789 by French Chemist Antoine Lavoisier . States that mass is neither created nor destroyed in any ordinary chemical reaction.

Alkaline Earth Metals (IIA family)

Found in Group 2 of the Periodic Table; all alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the -Alkaline Earth metals are not found free in nature. They are never found UNCOMBINED in nature. They have 2 valence electrons Alkaline earth metals include magnesium and calcium, among others.

Alkali Metals (IA family)

Found in the first column of the periodic table. They have a single electron in their outermost level, in other words, 1 valance electron. They are shiny, have low melting points and densities. They have the consistency of clay and are easily cut with a knife.

Atomic Number

Found near the top of the square. Refers to how many protons an atom of that element has. The atomic number is unique to that element. No two elements have the same atomic number (# of protons)

Isotope

Isotopes are atoms that have the same number of protons and electrons, but a different number of neutrons. Changing the number of neutrons in an atom does not change the element.

Metalloids

Means metal-like and have properties of both metal and non-metal. Solids Shiny or dull conduct electricity better than non metals but not as well as metals. Ductile and malleable.

Mixture

Mixtures consist of two or more substances that are only physically combined. Mixtures can be liquids, gases, and solids. •Smoke is a mixture of particles that are suspended in the air. •Tap water is a mixture of water and other particles. •Blood is a mixture with two main parts: plasma and red blood cells. When salt and water are combined, a mixture is created. Compounds in mixtures retain their individual properties. Mixtures can be separated by physical means

Nitrogen Family

Nitrogen Family is named after the element that makes up 75% of our atmosphere. This family includes non-metals, metalloids and metals. Atoms in the nitrogen family have 5 valence electrons. They tend to share electrons when they bond. Other elements in this family are phosphorus, arsenic, antimony, and bismuth.

Noble Gases (VIIIA family)

Noble gases are colorless gases and are extremely UN-REACTIVE. One important property of the noble gases is their INACTIVITY. They are inactive because their outermost energy level is FULL Because they do not readily combine with other elements to form compounds, the noble gases are called INERT The family of noble gases includes helium, neon, argon, krypton, xenon and radon. All noble gases are found in small amounts in the earth's atmosphere.

Oxygen Family

Oxygen Family has 6 valence electrons. Most elements in this family share electrons when forming compounds. Oxygen is the most abundant element in the earth's crust. It is extremely ACTIVE and combines with almost ALL elements.

Period (Scientific)

Periods are the horizontal rows on the periodic table. The atomic numbers increase from left to right. The elements in a period are not alike in properties because the properties change greatly across even given row. The first element in a period is always an extemely active solid. The last element in a period is always an inactive gas.

Boron Family

The Boron family is named after the 1st element in the family. Atoms in the Boron family have 3 valence electrons. This family includes a metalloid (boron) and the rest are metals. The Boron family includes the most abundant metal in the earth's crust which is aluminium.

Electron Cloud Model

The electron cloud model represents our current theory of the atom which shows that the electrons are not in a fixed orbit but an electron cloud

Halogen Family (VIIA family)

The elements in this family are fluorine, chlorine, bromine, iodine and astatine. Halogens have 7 valance electrons, which explains whey they are the most active non metals. They are NEVER found free in nature.

Hydrogen

The hydrogen square sits atop Family AI, but it is not a member of that family. It is in a class of its own. It is a gas at room temperature. It has 1 proton and 1 electron It needs only 1 electron to fill up it valence shell

Lanthanides and Actinides Series

The lanthanides and actinides are groups of elements in the periodic table. They are the elements that are often listed below the main section of the periodic table. There are thirty total elements in the lanthanides and actinides. They are often called the "inner transition metals." •The lanthanides and actinides are located mostly in the "f-block" of the periodic table.

Oxidation Number

The name for the process when oxygen combines with another element to form a compound. This periodic table contains the oxidation numbers of the elements. Bold numbers represent the more common oxidation states. Values in italics represent theoretical or unconfirmed oxidation numbers.

Valence Electron

The number of electrons with which a given atom generally bonds or number of bonds an atom forms. All elements in a family have the same number of valence electrons.

Chemical Reactivity

The rate at which a chemical substance tends to undergo a chemical reaction

Rare Earth Elements

The thirty rare earth elements are composed of the LANTHANIDE and ACTINIDE SERIES. One element of the lathanide series and most of the elements in the actinide series are called trans-uranium, which means SYNTHETIC or MAN-MADE

Transition Metals

These include elements in B Families copper, tin, zinc, iron, nickel, gold and silver Transition metals are good conductors of heat and electricity. Valence electrons flow very easily. The compounds of transition are usually brightly colored and are often used to color paints. Many transition metals combine chemically with oxygen to form compounds called oxides.

Transition elements

Transition elements have 1 or 2 valence electrons, which they lose when they from bonds with other atoms. Some transition elements can lose electrons in their next-to-outermost level Transition elements have properties similar to one another and to other metals, but their properties do not fit in with those of any other family

Family (Scientific)-Also called GROUPS

Vertical columns in the periodic table that have similar properties. The families are labeled 1-18 at the top of the columns • Examples of Families - Alkali Metals - Alkaline Earth Metals - Transition Metals - Halogen Gases - Noble Gases

Hydrogen + Oxygen

WATER

The rule of octet

When all atoms (except hydrogen) want to have 8 electrons in their very outermost energy level

Chemical Symbol

a notation of one or two letters representing a chemical element. Each element on the periodic table has a unique chemical symbol

What's in a square?

atomic number symbol atomic mass number of valance electrons state of matter at room temperature

Metal + Water reaction

corrosion

Dmitri Ivanovitch Mendeleev

created the first accepted version of the periodic table. He grouped elements according to their atomic mass and as he did he found that families had similar chemical properties Bland spaces were left open to add the new elements he predicted would occur.

Molecule

describes any atoms that are connected by chemical bonds. Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements.

Reactive

elements that bond easily with other elements to make compounds.

Metal

good conductors of heat and electricity shiny ductile (can be stretched into thin wires) malleable (can be pounded into thin sheets)

one Amu

is equal to the mass of one proton.

meaning of SYNTHETIC

man-made

Non Metals

poor conductors of heat and electricity not ductile not malleable solid non metals are brittle and break easily dull many non metals are gases

size of an electrons

remember that electrons are 2000 times smaller than one amu.

Bohr Diagram

shows that the electrons in atoms are in orbits of differing energy around the nucleus (think of planets orbiting around the sun).

Sodium + Chlorine =

sodium chloride or TABLE SALT

Pure Substances

substances that are made from one type of atom.

meaning of TRANS-URANIUM

synthetic or man-made

Electron Configuration

term used to refer to the arrangement of electrons within an atom.

Atomic Mass

the weight of the atom. It is derived by adding the # of protons with the number of neutrons.

Aristotle

theory of Air, water, fire and earth