Chapter 3 Atoms the building blocks of matter
if 3 g of element C combine with 8 g of element D to form compound CD, how many grams of D are needed to form compound CD2
16 g
6.022 x 10^23 is the number of particles in exactly one mole of a pure substance
Avogadro's number
why is Democritus's view of matter considered only an idea, while Dalton's view is considered a theory?
Democritus's idea of matter doesn't relate atoms to a measurable property, while Dalton's theory can be tested through quantitative experimentation
who named the nucleus and conducted the gold foil experiments
Rutherford
who discovered the electron and proposed the plum pudding model
Thomson
the smallest unit of an element that can exist either alone or in molecules containing the same or different elements is the
atom
the total number of protons in the nucleus of each atom of an element
atomic number
Two principles from Dalton's atomic theory that have been revised as new information has become available
atoms are divisible into smaller particales called subatomic particles, a given element can have atoms with different masses called isotopes
the weighted average of the atomic masses of the naturally occurring isotopes of an element
average atomic mass
In cathode-ray tubes, the cathode ray is emitted from the negative electrode, which is called the
cathode
transformation of a substance(s) into one or more new substances
chemical reaction
the subatomic particles that are least massive and most massive
electron and neutron
electrons are located in the
electron cloud
Give an example of a chemical or physical process that illustrated the law of conservation of mass
ice cubes have same mass when melted
atoms of the same element that have different masses
isotopes
mass is neither created nor destroyed during ordinary chemical reactions or physical changes
law of conservation of mass
a chemical compound contains the same elements in exactly the same proportions by mass regardless of the sample or the source of the compound
law of definite proportions
a chemical compound contains the same elements in exactly the same proportions by mss regardless of the size of the sample or source of the compound
law of definite proportions
if two or more different compounds are composed of the same tow elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
law of multiple proportions
the total number of protons and neutrons in the nucleus of an isotope
mass number
the mass of one mole of a pure substance
molar mass
are atoms positively, negatively, or neutrally charged?
neutrally
a nuclear particle that has no electrial charge
neutron
short range proton-neutron, proton proton, and neutron neutron forces hold the nuclear parcels together
nuclear forces
protons and neutrons located in the
nucleus
1/12 of the mass of a carbon-12 atom
oneatomic mass unit
a cathode ray produced in a gas-filled tube is deflected by a magnetic field. A wire carrying an electric current can be pulled by a magnetic field. A cathode ray is deflected away from a negatively charged object. What property of the cathode ray is shown by these phenomena?
particles are negatively charged
a positively charged particle found in the nucleus
proton
how is an atom neutral?
the nucleus is positive and electron cloud is negative
