chapter 3 test
antione-laurent de lavosier laid the foundation of chemical sciences by establishing the important laws of
what did antoine-laurent de lavosier have a strong influence on?
histories of chemistry and biology
who established the law of conservation of mass
antoine l lavoiser
which law states "mass can neither be created nor destroyed in a chemical reaction"?
law of conservation of mass
the substances that combine or react are called
the new substance/substances formed are called
which law says " if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is a always a ratio"?
law of multiple proportions
h2o has a ratio of
h2o2 has a ratio of
which law says "a chemical compound always contains exactly the same proportions of elements by mass"
law of constant porportions
what is another name for the law of constant proportions?
law of definite proportions
who developed the atomic theory
atoms of a given element are identical in
size, mass, and other properties
elements are made of extremelly small particles called
atoms cannot be
subdivided, created, or destroyed
atoms of different elements combine in what kind of ratios to form chemical compounds?
in chemical reactions, atoms are
combined, separated, or rearranged
all matter is composed of
atoms can be defined as the smallest particle of matter than can take part in what kind of reactions?
are atoms small?
yes, very very small
what charge do protons have
if you change the number of protons, what happens?
you change the element
what charge do neutrons have
neutral. NO charge
what charge do electrons have
if you change the number of electrons, what happens?
you change the charge
can atoms be seen with the naked eye?
do atoms exist in a free state in nature?
no, but they do take part in chemical reactions
the size of an atom is indicated by what
the mass of an atom is called what
the atomic number is equal to the number of _____ of each atom?
the mass number is the total number of ____ and ____ added together
protons and neutrons
what are isotopes
atoms of the same element that have different masses
whats the most stable carbon isotope?
avogadro's number is what
6.022 x 1023
group of 2 or more atoms that are chemically bonded together, that is, tightly held together by attractive forces
when converting from g to moles, what do you do?
you out the given gram over 1 and multiply by 1 mol over the atomic(or molar) mass of the given
when converting from mol to mass, what do you do?
you put the given over 1 and multiply by the molar/atomic mass over 1 mol
when converting mol to atoms, what do you do?
you put the given over 1 and multiply by 6.022 x 1023 over 1
when converting from grams to mass, what do you do?
you put the given over 1 and multiply by 1 mol over the atomic mass and then multiply by 6.022 x 1023 over 1 mol
when converting from atoms to moles, what do you do?
you put the given over 1 and multiply by 1 mol over 6.022 x 1023