chapter 4 test Flashcards
(37 cards)
what are the three types of changes in matter?
- chemical change
- physical change
- nuclear transformations
what is a physical change?
a physical change does not alter the characteristics or molecules of a substance. No new substance is formed
what is a chemical change?
a chemical change alters the characteristics of the molecules and changes the substance. new substances are formed
what is a chemical equation?
a chemical equation or chemical reaction is what is represented so that it can agree with the law of conservation of mass.
what phases can be identified to the elements on the periodic table?
l: liquid
s: solid
aq: aqueous
g: gas
what is the law of conservation of mass?
when a chemical reaction is performed, no matter is created or destroyed. the number and type of atoms must be balanced. If an equation is balanced, it obeys the law of conservation mass.
In Science, some molecules are not able to be alone when they are not part of a compound. What are they? remember the phrase! they are called diatomic molecules.
I-iodine h-hydrogen n-nitrogen br-bromine o-oxygen cl-chlorine f-fluorine
nomenclature has two main types of bonds. what are they?
- ionic bond
2. covalent bond
how are both bonds different?
- ionic bond: n.metal + metal.
2. covalent bond: n.metal + n.metal
how do we write out ionic bonds?
name the metal first, no prefix or suffix, second element end with suffix-ide.
if we have a polyatomic ion, name it no suffix.
how do we write out covalent bonds?
name the first n.metal that comes on the periodic table going from left to right. name the first element with the prefix, the second element, name prefix, and suffix-ide
how does the mole ratio help us?
it helps us convert between moles and mass. this is useful in questions because the calculations allow us to go from one form to another.
chemical reactions can be classified into two main categories. what are they? how can they be differentiated?
- endothermic, releases less energy, absorbs more. also seen as absorbing the energy from its surroundings. temperature decrease.
- exothermic, releases more energy than is absorbed. releases energy into its surroundings. temperature increase.
what is ENERGY? define.
energy is the ability to do work, effect change.
what are the 10 main energy types that we use in our everyday lives?
- thermal
- kinetic
- electrical
- chemical
- wind
- sound
- elastic
- radiation
- nuclear
- hydraulic
what is the law of conservation of energy?
this law means that energy can be transported from one place to another. also change from one form to another. energy cannot be created nor destroyed
what is energy transfer?
energy is moved from one place to another.
what is energy transformation?
energy that is being transformed from one form to another.
how is energy measured?
measure in joules
what are the chemical reactions?
- synthesis
- combustion
- decomposition
- precipitate/ double replacement
- acid-base neutralization
- photosynthesis
- cellular respiration
- oxidation
what is corrosion?
corrosion is the slow oxidation process of a metal when it is in contact with oxygen.
there are three types of combustion, what are they?
- slow combustion- releases energy in small amounts over a very long period of time ex: decomposition corrosion, cellular respiration
- rabid combustion- releases a lot of energy in a short amount of time ex: burning candle, combustion of gasoline
- spontaneous combustion- rapid combustion that starts without a spark ex: a forest fire, hot wood
how do we name acids?
there are two types of acids
- an acid containing a halogen.
- prefix: hydro
- suffix: -ic acid
EXAMPLE: HCl(aq) (covalent bond)- hydrogen monochloride becomes hydrochlorIC acid - an acid containing a polyatomic ion.
- suffix: -ic acid
- basename + -ic acid
EXAMPLE: H3PO4- phosphate becomes phosphorIC acid
what is a nuclear transformation in chemistry?
these reactions involve the nucleus of the atom of a molecule. “normal” chemical reactions involve the valence electrons, not the protons + neutrons which are in the nucleus. the nucleus opens, protons and neutrons & rearranged. the opening of the nucleus causes a large release of energy that usually holds the nucleus together.
