Exams 1-3 review Flashcards
true or false: nonmetals tend to lose electrons
false
true or false: experiments are needed to validate a theory
true
true or false: once a theory is proposed, it is considered fact
false
true or false: an observation explains why nature does something
false
true or false: a scientific law summarizes a series of related observations
true
true or false: in both solids and liquids, the atoms or molecules pack closely to one another
true
true or false: liquids are highly compressible
false
true or false: protons and electrons have opposite but equal in magnitude charges
true
true or false: alkali metals are generally not reactive
false
a substance that cannot be chemically broken down into simpler substances is
an element
a substance composed of 2+ elements in a fixed, definite proportion is a
compound
isotopes of the same element differ only in number of :
neutrons
physical or chemical change?
sugar heated to caramel
C
physical or chemical change?
water cooled to ice
P
physical or chemical change?
baking soda dissolved in water
P
how many SF in 0.9810
4
a covalent bond is best described as:
a pair of electrons holding neighboring nuclei at a fixed distance
name HF
hydrofluoric acid
name CaS
calcium sulfide
name Ni2(SO4)3
nickel (III) sulfate
name HClO3
chloric acid
name P4O10
tetraphosphourous decoxide
formula for sulfurous acid:
H2SO3
define a limiting reagent
the reagent that runs out first and determines how much product is made
how can you tell if a reaction is an oxidation-reduction reaction?
check oxidation states; changing oxidation states indicates transfer of E-
as volume increases, pressure
decreases
as temperature increases, pressure
increases
what is the maximum # of D orbitals in any energy level?
5
if N=2, what can L be?
0, 1
Where does energy absorbed during an endothermic reaction go?
this energy raises the potential energy of the bonds formed in the products thereby “storing” that energy
Why do atoms emit only certain wavelengths of light when they are excited? (why do line spectra exist)?
electrons can occupy only certain energy levels (n=1,2…) and nothing in between, which means that they transition between those energy levels, the exact and corresponding energy is emitted as photons, with no energies in between
Which noble gas has the highest ionization energy? explain
He because it is smallest and most difficult to remove the highest energy valence electron
