Final Flashcards
which of the following groups contain three elements with stable electron configuration?
helium exon neon
Typically atoms gain or lose electrons to acheive
a stable electron configuration
Ionization energies tend to
increase from left to right across a period
the formation of an ionic bond invovles the
transfer of eloectrons
when 2 atoms of the same nonmetal ewact, they often from a
diatonmic metal
an elemet that loses 1 valence electron would have a ____ chargre
1+
in an electron dot diagram the dots represent
the valence electrons
In electron dot diagram, the element’s symbol represents
the nucleus and the inner energy levels
what type of elements will form an ionic bond?
metals with nonmetals
what type of elements will form a covalent bond
nonmetals with nonmetals
what substance would be an example of a polar molecule?
water
To clean an oil-base paint out of a brush, a person could use
acetone
The water H20 is polar because it contains 2 poalr single bonds and
its molecule has a bent shape
Every compound has to have an overall___ charge
neutral
the formation of a covalent bond invovles the
sharing of electrons
T/F a reactant is formed as a result of a chemical reaction
f
T/F the rusting of iron is an example of a chemical reaction
t
T/F if energy is given off as a result of a reaction, the total mass of the reactants will not be equal the total mass of the products
f
T/F subscripts may be chanfed in irderf to balance a chemical equations
f
T/F in a single-replacement reaction, an uncombined element replaces an element that is part of a compound
t
T/F in a synthesis reaction, two compounds react to form two compounds
f
T/F noth exothefrmic and endothermic reactions require activation energy
t
T/F Catalysts are unchaged after being invovled in a chemical reaction
t
T/F a synthesis reaction is the opposite of a decomposition reaction
t
One mole is a counting unit equal to 6.02 x 10(23rd power)
t
WHen a chemical reaction oocur, there is always a change in
both energy and properties of the reacting substance
when a chemical reaction occurs
new substances are formed
when two substances combine chemically, the properties of the properties of the products are
different from the properties of the reactants `
what doesn’t occur as a result of a chemcial reaction
new atoms may form
what information does a chemical equation giver about a chemical reaction
both the kinds and numbers of atoms invoved in the reaction
The law of converstion of mass states that
in a chemical reaction, the total mass of the reactants must be equal to the total mass of the oroducts
A log is burning in a fireplace. If the amount of oxygen reaching the log is decreaae, what will happen
the reaction rate decreases
In an exothermic reaction
energy is released
When a chemical reaction occurs
an energy change always occurs
enzymes increase the rate oc chemical reactions in the body by
acting as catalysts
comubstion or burning
is always am exothermic reaction
As a result of an endotherimuc reaction
The products have more energy than the reactants
while preforming a chemical reacton, a student touches the side of their container holding the reacts and notices that it feels warm. the reaction must be
exothermic
in generl, increasing the concentration of reactants causes the reaction to occur
faster
Breaking a soid reactant into smaller pieces results in
an increase in the reaction rate
An increase in temperature generally increases reaction rate because high-temperature molecules
are likely to collide more frequently
A catalyst is a
substance that lowers the activation engery needed for a reaction
