31 terms

Ch4 Atoms and Elements

Atoms and Elements
What are pure substances from which all other things are built?
What are one or two letter abbreviations reflecting the names of elements referred to as?
chemical symbols
two letters capitalized represents two elements
What russian chemist arranged 60 elements known at that time as two groups with similar properties and placed them in order of increasing atomic masses. and what is this arrangement now named
Dmitri Mendeleev the periodic table with 117 elements
In the periodic table what is each horizontal row called? And how many horizontal rows are there in the periodic tab?
period, 7
List the elements in row 1
hydrogen and helium
What is each vertical column on the periodic table called?
group, each group has a number assigned to each group
List the names of the groups occurring in the periodic table?
Alkali Metals, Alkaline Earth Metals, Transitional Elements, Halogens, Nobles Gases
What elements are found in the alkali group?
Group 1A elements:
Lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr)
What are the characteristics of the alkali group?
Elements of this group are soft, shiny metals that are good conductors of heat and electricity and have relatively low melting points.
Alkali metals react vigorously with water and form white products when they combine with oxygen.
What elements are found in the alkaline earth metals?
Group 2A elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra).
They are shiny metals but are not as reactive as group 1A
Are found on the right side of the periodic table in group 7A. They include: fluorine (F), Chlorine (Cl), bromine (Br), iodine (I), and astatine (At)
The halogens especially fluorine and chlorine are highly reactive and form compounds with most elements.
Noble gases
Group 8A (18) helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
Noble gases are quite un-reactive and are seldom found in combination with other elements.
What are the color codes for metals, metalloids, non metals?
Yellow=non metals, Blue= metals, green= metalloids
Metal characteristics
shiny solid, made into wires ductile or hammered into flat sheets malleable, good conductors of heat, electricity. Usually melt at high temperatures. solids at room temperature. except mercury which is liquid
some metals: sodium, magnesium,cooper, gold,silver, iron,tin
Non metal characteristics
not especially shiny, malleable, or ductile,poor conductors of heat and electricity. Low melting point and low density. Hydrogen carbon, nitrogen, oxygen, chlorine, sulfur
B,Si,Ge, As,Sb, Te, Po, At
Metalloids are elements that exhibit some properties that are typical of metals and other properties that are characteristic of the nonmetals. Metalloid are semiconductors because they can be easily modified to function as conductors or insulators
What elements compromise macrominerals
Ca, P, K, Cl, S, Na, Mg
Are involved in positive and negative ion formation of bones, teeth, maintenance of heart and blood vessels, muscle contraction, nerve impulses, acid base balance of fluids, regulation of cellular metabolism.
Which 4 elements make up 96% of body mass?
oxygen, carbon, hydrogen, nitrogen
Define an atom
smallest particle of an element that retains the characteristic of that element
What theory did John Dalton propose?
atomic theory that proposed that atoms were responsible for the combination of elements found in compound.
1) all matter is made up of tiny particles called atoms
2) all atoms of a given element are identical to one another and different from atoms of other elements
3) atoms of 2 or more elements combine to form compounds. a particular compound is always made up of same kinds of atoms and same number of each kind of atom.
4) a chemical reaction involves rearranging, separation, or combination of atoms. atoms are never created or destroyed during a chemical reaction.
Name the microscope that produces images of individual atoms
scanning tunneling microscope
What determines the mass of an atom?
The proton and neutron mass
What the charge of a proton?
Positive, p+
Protons are attracted to electrons
What kind of charge does a neutron have?
Neutral, location inside nucleus
Name 3 subatomic particles?
Proton, neutron,electron
What is the mass of an electron?
0.00055 amu
What kind of charge does electron have?
1- location outside nucleus
What is the the atomic number?
is the number of protons in an atom
Protons in neutrally charged atom equal the number of electrons
What is the mass of an atom?
the mass of an atom is the sum of the neutrons and protons
Whats the formula for determining the number of neutrons?
Mass-atomic number (# protons)=#neutrons
Define isotopes
Isotopes are atoms of the same element that have a different # neutrons