chem chapter 2
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chem chapter 2
chapter 2 powepoint
opposite charges ____. like charges ____
__ are extremely small particles that are unseen by the naked eye
this instrument allows you to move individual atoms across the surface
scanning tunneling microscoope
center of the atom?
fluffy stuff on the outside of the nucleus
nucleus has the ?
protons and neutrons
protons ____ change, electrons and neutrons ___ change
when # of protons and neutrons are the same
what unit is used instead of grams?
amu (atomic mass unit)
where is all the mass of the atom located?
in the middle
what define the element
the number of protons
who discovered the periodic table
A groups are known as the?
main group or representative elements
alkaline earth metal
B groups are known as the?
___ have properties of some metals and nonmetals
a substance or mixture that has a characteristic luster and is generally a good conductor of heat or electricity
an element that does not exhibit the characteristics of the metal
description of metals?
solid and room temp
when metals lose electrons they form
cations in reactions
description of nonmetals
solid, liquid, gas
poor conductors of heat and electricity
solids are brittle
when nonmetals gain electrons, they
metalloids are known as?
example of metals?
example of nonmetals?
example of metalloids?
number of protons in the nucleus
total number of protons and neutrons in the nucleus
same number of protons, but number of neutrons change
for isotopes, average atomic mass is calculated by?
using weighted average
average atomic mass?
(mass of isotope)x(fractional abundance 1) +(mass of isotope 2)x(fractional abundance 2)....
protons + neutrons
color Na burns
color K burns?
color Li burns?
color Ba burns?
1 orbital, 2 electrons
3 orbitals, 6 electrons
5 orbitals, 10 electrons
7 orbitals, 14 electrons
s is what shape?
p is what shape?
d is what shape?
3 principles for electron configuration?
paul exclusion says?
an orbital can hold only 2 electrons
electrons begin filling in the lowest energy level
electrons separate before they pair
the electrons in the outermost principle quantum level of an atom?
charged particles are called?
when atoms gain electrons, they become negatively charged ions called
when atoms lose electrons they become positively charged ions called
atoms lose or gain electrons to look the same as a noble gase
defined as half the distance between the nuclei in a molecule consisting of 2 identical atoms
atomic radii gets bigger as?
you move to the left and down on the periodic table
elements in a group form ions of the
when an atoms loses and electron, it has a ____ charge and becomes ____
when an atom gains an electrons, it has a ____ charge and becomes ____
the quantity of energy required to remove an electron from the gaseous atom or ion