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Prentice Hall Science Explorer Chemical building blocks Chapter 3

What did Mendeleev do?
He created and organized the periodic table.
Atomic Mass
the average mass of one atom of the element.
Periodic table
a regular repeated pattern
What are atoms made up of?
Sub atomic particles, electrons, neutrons, and protons
What is inside the nucleus?
Protons and neutrons
What electrical charges do protons carry? Neutrons? Electrons?
Postitive, none, negative
Do electrons move constantly around the nucleus?
Atomic number
the number of protons in its nucleus
Every atom of a particular element contains the same number of --------------------? But varies in--------------------?
Protons; neutrons
Protons and electrons are always the same number. True or false?
To find the number of neutrons you do what?
You subtract the atomic number from the atomic mass
When is a valance electron less reactive? When is it more reactive?
It is less reactive when there are more valance electrons
It is more reactive when there are less valance electrons
How do chemists classify a metal
They classify them on their physical properties such as; hardness, shininess, malleability and ductility.
A material that can be pounded in to shapes
a material that can be pulled out, or drawn into a long wire
transmit heat and electricity easily
attracted and made into magnets
Most metals are..?
Solid at room temperature
ease and speed with which an element combines, reacts with other elements and compounds
When a metal wears away because the soft metals oxide flakes off
a mixture of metals
the metals in a group or family have similar properties and these family properties change gradually as you move across the table. True or false?
Alkali metals
Super reactive metals that are never found uncombined in nature
How many valance electrons do Alkali metals have?
one. Easily transferred to other atoms during chemical change.
Alkaline earth metals
Not as reactive as Alkali metals. Never found uncombined in nature.
Transition metals
Groups 3 through 12. form a bridge between the very reactive metals on the left side and the less reactive metals in the right side.
Metals in Mixed Groups
groups 13 through 16 incluedes metals, non metals, and metalloids
Bottom of the periodic table. Soft, shiny, malleable
Unstable elements at the bottom of the peridoc table
non metal
located to the right of the zig zag line in the periodic table
Nonmetal elemnts are gases at room temperature? true or false?
True. In general physical properties of metals are opposite to those that characterize the metals.
Diatomic Molecules
Two identical atoms formed by nonmetal compounds
Group 18
Nonmetals excusively
Group 14
Carbon family.
Group 15
Nitrogen Family. Contains elements that have 5 valance electrons in their atoms.
Oxygen Family
Group 16. Contains elements that have 6 valance electrons in their atoms. Typically gains or shares twoelectrons when it reacts.
Group 17
Halogen family. All but one are non metals. all share simliar properties. Very reactive.
In what order did Mendeleev arrange the elements in the periodic table?
in order pf increasing atomic mass
What can you predict about an element from its posotion on the peridoc table?
An elements properties
What do elements in the same column in the periodic table have in common?
the elements have the same number and arragement of valance electrons
Valance electron
is involved in the transfer or sharing of electrons.
The number of electrons on the outer(last) shell
Sodium and calcium are in different families of metals. Name the families of metals in which they belong, and describe each family's characteristics.
Sodium(Na) belong to Group 1 where as calcium (Ca) belongs to Group 2. Both families are highly reactive and Na is a alkali metal and Ca is a alkaline earth metal. Na is highly reactive. Ca is not AS reactive.
Would a metal in group 13 be more reactive than a metal in group 1? Explain.
No, because Group 1(Alkali metals) metals are VERY reactive where as group 14(Metals in Mixed Groups) are not as reactive.
In what period are lanthanides and actinides?
These elements fit in periods 6 and 7
Noble Gases
Group 18, do not ordainarly form compounds. they do not gain or loose or share electrons.
On the border between the metals
What is metalloids most useful property?
Their ablitity to conduct electricity
substances that under some conditions can carry electricity like a metal, while under some additions other conditions cannot, like a nonmetal.
state of matter, atoms are stripped of their electrons and the nucllei are packed closely together.
nuclear fusion
atomic nuclei combine to form a larger nucleus, releasing huge amounts of energy in the process.
How do starts create heavier elements?
In a nuclear fusion tah tcombines smaller nuclei into larger nuclei
a tremendiys explosion that breaks apart a massive start, producing temperatures up to one billion degrees