Quiz 3 Flashcards
who created atomic theory and what does it mean?
john dalton
all matter is composed of atoms
what is john dalton’s atomic theory? what are the 3 parts.
1) elements is made of “indestructible” particles called atoms
2) 2 atoms of same element will be “completly identical”
3) atoms combine in simple whole ratio to form compounds. fractions of atoms don’t exist
plum pudding model
- what did it state
- who discovered it
- what did he discover exactly?
- negative particles must be evenly
distrubuted in a bigger particle
–JJ Thompson
-electrons
nuclear atom
- what experiment was executed to discover it and explain the reasoning
- who discovered
- what did he discover with this experiment?
- gold foil experiment; they learned that there was a positive mass that was repelling the alpha (+) particles that are being shot at it.
- rutherford
- the proton
who discovered the neutron?
Chadwick
how were electrons seen in the past vs. now?
they used to be seem like raisins embedded in a pudding but now they are seem as a cloud surrounding the nucleus
how were positive charges seen back then vs. now?
they used to be seen like past electrons, evenly spread out throughout the atom.
how was the mass of an atom seen before vs. now
mass use to be spread out throughout the atom but now it’s concentrated int he nuculis
what is the fundamental physical property of protons and electrons?
electrical charge
is the neutron or proton heavier
neutron
correct dalton’s outdated atomic theory
1) atoms can be destructed, but not the subatomic particles
2) same elements will not be exactly the same bc some have diff masses.
3) this one is still correct
who invented first draft of periodic table
Dmitri Mendeleev
on the periodic table, what are rows and columns calle?
rows: periods
columns: groups/family
what is special about columns?
they share similar chem properties
what groups is the main group element made up of?
group 1A-8A
what are 2 characteristics of main group elements?
1) most abundant in the universe
2) properties tend to be predictable based on their positions in the periodic table
where are the transition metals
the elements not included in main group
what is a characteristic of transition metals
their properties are less predictable than main group
what is the name for: IA IIA VIIA VIIIA
alkali metals
alkali earth metals
halogens
noble gases
what are 5 properties of metals?
- ductile (can be turned into wires)
- malleable ( can be hammered without cracking)
- luster
- good conductor of heat
- and electricity
what are the predictable charges of group 1A, 2A, and 7A
1A: +1
2A: +2
7A; -2
what is another way to refer to atomic number?
Z
AN
whats another way to refer to mass number
A
MN
mass number
of protons + # of neutron
