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81 terms

Science! 2.1 for Jess

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group
a vertical column of elements in the periodic table; elements in a group share chemical properties
period
a horizontal row of elements in the periodic table
Mixture
separated mechanically. no fromula
atomic number
the number of protons in the nucleus of an atom
atomic mass
total mass of the protons and neutrons in an atom, measured in atomic mass units
electronegativity
The stength in which an atom holds its electrons. the tendency of an atom to attract electrons in the formation of an ionic bond. increases as you go up a group and from left to right on the periodic table.
Electronegativity in non-metals are...
high, greedy for more
80% of the elements are...
Metals.
Electronegativity in metals is...
low, litttle control
Metals
electrical conductivity, luster, malleability, ductility, thermal conductivity. atoms of metals exist in lattices. All bu mecurty are solid at room temperature.
cation
a positively charged ion
anion
a negatively charged ion
Elements that have properties of both metals and nonmetals are called
metalloids
How are the electrons in a "cloud" of electrons like the blade of the fan?
Electrons in a cloud move in such a way around the nucleus that is impossible to identify their positions.
How does the mass of a proton compare to the mass of an electron?
A proton is 2000 times more massive than an electron. Or an electron is 1/2000 the mass of a proton
Where is the majority of the volume found in an atom?
the electron cloud
What are the smallest particles that make up elements and compounds?
atoms
What happens if protons are added to an atom?
The atom becomes a different element
Non Metals
-poor conductors/ do not conduct (insulators)
-melting and boiling points are so low that they are usually liquids or gases at room temperature
-brittle and tend to crumble
-dull, little or no shine/luster

Group 8 atoms are the only ones that exist by themselves. MOst others form molecules that contain 2 atoms. Some form lattics.
ion
number of electrons and protons in not eqal
Who predicted new elements and is credited with creating the periodic table?
Mendeleev
How did Mendeleev arrange the elements? How is the modern periodic table organized?
Mendeleev-increasing atomic mass
Now-increasing atomic number (number of protons)
Very similar
In a fight or chemical reaction. Metals vs Non metals
non metals try to rob metals of their outer sell electron (valance)> non metals from a positive ion, their name usually changes. Metals loose and therefore form a negative ion.
How can the properties of an element be predicted?
From its location on the periodic table
Isotope
an atom in which the number of protons and neutrons difer.
Where are the semimetals located on the periodic table?
Going down the "staircase" or on the zig zag line
What period are the lanthanides located?
Period 6
What period are the actinides located?
Period 7
How do they alkali metals react?
They lose one electron
How do the alkaline earth metals react?
They lose two electron
How do the halogens react?
They gain one electron
How reactive are the inert gases?
Completely unreactive
Atomic mass increases
as you go from left to right
How does reactivity change in metals as you go from the left to the right in the periodic table.
In general, reactivity decreases.
How does the reactivity change as you go down the alkali metal. What is the least and most reactive alkali metals?
As you go down, the metals become more reactive. Lithium is the least reactive and francium is the most reactive.
Hydrogen is in group 1. Is it an alkali metal or a nonmetal? Why is is it in group 1?
Non metal. It has one valence electron, so it is in group 1. It cannot be placed with halogens as it has just one valence
How many periods are in the periodic table?
7
How many groups are in the periodic table?
18
What information is listed in an element's square in the periodic table?
atomic number, chemical symbol, element name, atomic mass
What are 8 physical properties of metals?
malleability, ductility, luster, thermal conductivity, electrical conductivity, high melting points, solid at room temperature, and magnetism.
Patina and rust are examples of what?
oxidation-oxygen reacting with a metal. Patina is oxygen reacting with copper (ex. old penny or the Statue of Liberty). Rust is oxygen reacting with iron.
Discuss the relative hardness of pure alkali metals compared to pure alkaline earth metals.
Some alkali metals are so soft they can be cut with a plastic knife. Alkaline earth are harder than alkali metals
Is reactivity a chemical or physical property? Why?
Chemical property. New substances are being created.
What is one physical property characteristic of all transition metals?
good conductors of electricity
What are the most reactive metals
alkali metals
what are the most reactive non-metals?
the halogens
What is the second family called?
alkaline earth metals
What are the metals in the center called?
Transition metals
Are families up and down or left and right
up and down
What are the significance of periods?
They have similar traits that continue on an exponential track
What are valance electrons?
The electrons on the outermost shell on an atom
How many electrons can the K shell hold?
2 electrons
What is a lewis dot diagram?
this shows only the Valence electrons
What is a Bohr model
this shows all electrons in an atom
How many electrons can the L shell hold?
8
How many electrons can the M shell hold?
18
How many electrons can the N shell hold?
32
What is the octet rule?
Atoms with 8 electrons are not reactive
Characteristics of metals
shiny, bright luster, good conductors
Characteristics of non-metals
dull, dull luster, bad conductors
Characteristics of metalloids
Metalloids typically conduct heat and electricity better than nonmetals but not as well as metals. They are solids. They conduct heat and electricity. They insulate at low temperatures. They conduct at high temperatures.
Group VIII
noble gases
What are the three classes of elements?
Metals, nonmetals, and metalloids
Why is a row called a period?
Because the properties of elemnts in a row follow a periodic pattern
Characteristics given in a square on the periodic table
Atomic number, atomic mass, chemical symbol, and element name
Group 13
Boron group
Group 3-12
Transition metals
Dmitri Mendeleev
Russian chemist; contructed the first periodic table and arranged the elements in increasing atomic mass.
Law of Octaves
States that in every 8th interval, the elements have the same characteristics.
Periodic Law
States, "When the elements are arranged in increasing atomic number, similar properties of elements appear at regular intervals or periodically."
Where do the most reactive metals lie on the periodic table
bottom left
Where are the most reactive non metals?
upper right
Blocks of elements without group numbers
transition elements, the lanthanides and the actnides.
electronegativity
The strength with wich as atom holds its electrons. Metal atoms have a low electronegativity and non- metals have a high electronegativity. Metals have little control over their outer elextrons while non-metals have tight control and are 'greedy' for more. Non metals try to rob metals of their valence electrons.
Hydrogen
If it looses one electron it beceomes the hydroge ion H+. if it gains one it will become the hydride ion h-. It can act like a group I or a group VII element depending on what i comes into contact with.
Group V111 Noble Gases
-colourless gases
-stable and react really under extreme circumstances
-helium is very light
VII Halogens
-forms ions with a charge of -1
-are never found in their pure form in nature but are in various types of salts
-coloured and poisonous vapours
-all form molecules, each being made up of two atoms
-all convert Hydrogen sulfide into solfur.
-react similar to iron
Alkali Metals
-form +1 ions
-very reactive
-typical metallic properties
-similar chemically extreme behaviours
alkaline earths
similar to group 1 but less reactive.
Group IV
-as non metals, a metalloid and metals.
Transition metals
-useful, colourful valuable metals such as iron coppor zinc gold and silver.
Similar properties.