Atomic Theory Flashcards
what is chemistry?
the study of matter
-matter is anything with mass or volume
what is an element?
pure substance made up of one type of atom
-cannot be broken down
what is a compound?
pure substance made up of two or more elements
-can be broken down
what are subatomic particles?
particles that make up an atom
location of electron plus basic info (charge, relative mass)?
shells surround the nucleas
- charge: negative one (-1)
- mass: 1
location of proton plus basic info (charge, relative mass)?
nucleus
- charge: positive one (+1)
- mass: 1836
location of neutron plus basic info (charge, relative mass)?
nucleus
- charge: neutral (0)
- mass: 1837
why is nucleus positively charged overall?
neutrons have no charge
what occupies the most volume in an atom?
electrons
what is a neutral atom?
protons and electrons are the same
what is an ion?
a charged atom/atom has lost of gained electrons to become a electrically charged particle
-does not have equal amount of protons and electrons
what is the atomic number?
number of protons in nucleus
what is the mass number?
sum of protons and neutrons in nucleus
- mass of atom comes mostly from p and n bc electrons almost have no weight
- is whole number
what is an isotope?
atoms with different number of neutrons (protons are the same)
what is the atomic mass?
average mass of all atoms in an element
- different isotopes of atoms exist resulting in different weights of atoms
- is decimal number
how to find mass number?
number of protons + number of neutrons
who invented the periodic table?
dmitri mendeleev
where are the metals found on the pt?
left side
where are the non-metals found on the pt?
right side
what are the elements along the staircase called?
metalloids
what are horizontal rows of the pt called?
periods
what are vertical rows of the pt called?
families/groups
alkali metals info:
- side and group
- reactive level
- examples
left side group 1
highly reactive
lithium, sodium, potassium
alkaline earth metals info:
- side and group
- reactive level
- examples
left side group 2
somewhat reactive but not as much as alkali metals
beryllium, magnesium, calcium
halogen non metals info:
- side and group
- reactive level
- examples
right side group 17
very reactive
flourine, chlorine, bromium, iodine
noble gases info:
- side and group
- reactive level
- examples
right side group 18
highly non reactive
six noble gases: helium, argon, krypton, xenon, neon, radon
what happens when atoms lose or gain electrons?
they become ions
what happens to an atom that loses electrons and which atoms will lose electrons?
- becomes positively charged
- all metals lose electrons
what happens to an atom that gains electrons and which atoms will gain electrons?
- becomes negatively charged
- all non metals gain electrons
what group will not form ions?
noble gases
what are multivalent metals?
metals that can form ions in multiple ways depending on the chemical reaction they undergo
how to find number of electrons?
protons - charge
how to find number of neutrons?
mass number - protons
how to find mass number?
protons + neutrons
what is a charge of 0?
neutral atom
what is positive/negative charge?
ion
how many electrons can the first shell hold?
2
how many electrons can the second shell hold?
8
how many electrons can the third shell hold?
8
what does the period number represent?
number of occupied shells of atom
what do the elements in the same family have in common?
same number of electrons on outermost shell
what is the valence shell and electrons?
outermost shell and electrons in that shell
what happens when you move left to right across a period?
one electron is added to the valence shell
what is a full set of eight electrons called?
stable octet
what happens when you change the number of protons?
new element created
what happens when you change the number of neutrons?
different isotope created
what happens when you change the number of electrons?
ion is produce
why do other elements try to imitate noble gases?
noble gases are stable and have stable octet (full valence shells)
how to other elements imitate nobles gases?
by losing or gaining electrons from other atoms in chemical reactions
what happens when a metal meets a non metal?
they exchange electrons and have opposite charges that attract
what is an atom?
smallest particle of an element that retains the property of that element
