section one test Flashcards
what is an Element?
an element is a substance made of only one type of atom that cannot be separated into something simpler.
a basic structure of an atom
an atom is built up of neutrons, protons, and electrons.
compound
two or more substances that are chemically bonded
Mixture
when there are two substances are close but not chemically bonded.
Diatomic Elements
gases that form molecules because they do not have full valence shells.
Ways to remember the diatomic elements.
Have No Fear Of Ice Cold Beer. (hydrogen, nitrogen, fluorine, oxygen, iodine, chlorine, Bromine.
Atomic Number
The number of protons in the nucleus of an element. it determines its place in the periodic table.
Mass Number
The total number of protons and neutrons in an element.
Atoms why don’t they have a charge?
they have no charge because they always have the same amount of protons in the nucleus as electrons making them neutral.
Isotopes
Isotopes are elements of the same type with more neutrons than protons in its nucleus.
subatomic particles
neutron, electron, proton
AMU (Atomic Mass Number)
each subatomic particle has a weight but, it is so small they have their own unit. proton=1 AMU neutron=1Amu Electron= 1/2000 (AMU)
Ion
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. This charge can be positive or negative.
Cation
A Cation is a positively charged ion. this when an atom loses an electron to have a full valence shell.
Anion
An Anion is a negatively charged ion. this is where it has to gain electrons to have a full valence shell. E.G. hydrogen.
Why is an Ion charged?
because the element has more or fewer electrons than protons in its nucleus.
why do elements in the same group act similarly?
they act similarly because they have the same amount of electrons in their valence shells.
The maximum number of electrons in the first 4 energy levels.
2,8,8,18
Why does chlorine not have a whole mass?
it doesn’t have a whole mass number because it has two common isotopes and the RELATIVE ATOMIC MASS NUMBER comes out at 35.5 as chlorine-35(17 protons 18 neutrons) is found %75 of the time and Chlorine -37(17 protons 20 neutrons) is found %25 of the time.
typical properties of transition metals
they form colored compounds.
they are good conductors of heat and electricity.
they can be hammered or bent into shape easily.
they are less reactive than alkali metals such as sodium.
they have high melting points
Why is mercury different from typical transition metals?
because it is a liquid at room temperature.
The trend in reactivity in Group 1
As you go down the group, the Atomic Number changes and it decreases the melting point but makes it denser.
Atoms
they make up everything. An atom is the smallest part of an element that can exist. 0 charge overall
Molecules
small groups of atoms covalently bonded.
Groups
they tell you how many electrons are in the outer shell.
the elements in the periodic table are arranged in…
increasing proton number
Relative charge
protons (+1)
neutrons(0)
electrons(-1)
the radius of atom and nucleus
atoms=0.1nm (1x10 to the power of -10 meters)
nucleus: 1/10,000 of an atom
valence shell
the highest energy level.
Why are groups useful
because elements in the same groups have similar chemical and physical properties. This is because they have the same number of valence electrons.
Monatomic Elements
consist of single atoms.
noble gases are monatomic. they are very stable an unreactive making it super hard for them to form ions or bonds.
Hydrocarbons
Meth-ane: 1 carbon Eth-ane: 2 Carbon Prop-ane: 3 Carbon But-ane: 4 Carbon hept-ane : 5 Carbon
General formula= CnH2n+2 (n= carbon number)
Neutrons in an element =
= mass Number - Atomic Number. Atomic Number= amount of protons and electrons/e.g. mass #=56 Atomic#=26 neutrons=30
more group information
the amount of electrons in the valance shell is the same as the group. e.g. fluorine is in group 7. It has 7 electrons in its valence shell.
elements are arranged in
Atomic mass.
Period
a Period is a horizontal row in the periodic table.
Ionic Lattice
Structure and bonding. Ionic bonds are the electrostatic forces of attraction between oppositely-charged ions. The oppositely-charged ions are arranged in a regular way to form a giant ionic lattice.
Periodic Law
The properties of the elements must repeat periodically.
Group 1 elements are called
alkali metals
group 2 elements are called
alkali earth metals
group 7 elements are called
Halogens
group 8/0 elements are called
noble gases
within a group, the atomic radius goes.. within a period what happens to the atomic radius as the atomic number increases?
the atomic radius increases while in a period the atomic radius decreases.
relative atomic mass
the ratio of the average mass of one atom of an element to one-twelfth of the mass of a carbon -12
relative isotopic mass
the mass of an atom of an isotope compared with one-twelfth carbon -12 atom.
Ionic/covalent/metalic
Ionic bond= between oppositely charged ions
covalent= shared pairs of valence electrons between atoms.
Metalic= electrostatic attraction between delocalised electrons and positive nucleus
Sulfate
SO4 (2-)
Nitrate
NO3 (-)
Chloride
Cl (
Phosphate
PO4
Ethanoate
COO
Hydroxide
OH
