Chapter 3 Flashcards
Law of conservation of mass
Mass is neither created nor destroyed during ordinary chemical reactions or physical changes
Law of definite proportions
A chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound
Law of multiple proportions
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 second element is always a ratio of small whole numbers
What is the nucleus and what is its charge?
A very positive small region located at the center of an atom
What is the charge, size, mass on a proton?
Positive, slightly smaller than neutron, 1
What is the charge, mass and size on a eletron?
Negative, very tiny, 0
What are neutrons, protons and electrons referred to?
Subatomic particles
Why are atoms electrically neutral?
They contain equal numbers of protons and electrons
What is an atom?
The smallest particle of an element that retains the chemical properties of that element
What determines the atom’s identity?
The number of protons
What is the radius of the an atom?
The distance from the center of the nucleus to the outer portion of its electron cloud, expressed in picometer,pm
What is the atomic number?
The number of protons
How are isotopes defined?
They have a different number of neutrons
What is the mass number?
The total number of protons and neutrons
What is the term for a specific isotope of an element?
Nuclide
What is one atomic mass unit?
1/12 the mass of a carbon-12 atom
How can you find the average atomic mass?
Multiplying the atomic mass of each isotope by its relative abundance (decimal) and adding the results
What is the SI unit for amount of substance?
Mole
How is molar mass written?
g/mol
What is Avogadro’s number?
6.0221415 x 10^23
What is the molar mass of an element?
The atomic mass of the element in atomic mass units
What is the charge on a neutron?
Neutral, biggest by a little bit, 1
Chemical reaction
The transformation of a substance or substances into one or more new substances
What are nuclear forces?
Th short range p-n, p-p, and n-n forces that hold the nuclear particles together
What is the relationship between the magnitude of the charges of protons and electrons?
They are equal
Who did the oil drop experiment and what did it show?
Robert A. Millikan, mass of electron
Who did the gold foil experiment (3), what was it, what did it prove (3)?
Ernest Rutherford, Hans Geiger, and Ernest Marsden, one in 8000 particles bounced back-> dense positive bundle (nucleus) and elections move around the nucleus very far away, which proves the plum pudding model false
What are the five parts of dalton’s theory?
All matter is composed of extremely small particles called atoms, atoms of a given element are identical in size+mass+other properties: atoms of different elements differ in size+mass and other properties(lodp), atoms cannot be subdivided+created or destroyed(locom), atoms of different elements combine in simple whole-number ratios to form chemical compounds, in chemical reactions atoms are separated combined or rearranged
Describe the cathode-ray experiment, who was in charge and his model, and what it proved.
When current was passed through the tube, the surface of the opposite side glowed. The ray was bent away from the magnet, proving the ray was made of negatively charged particles, which had a high mass-charge ratio Joseph John Thomson-plum pudding
What did Chadwick do?
He discovered neutrons
What is hyphen notation?
Name of element- mass number
What is nuclear symbol notation?
Nuclear symbol with a super script of mass number and a subscript of atomic number
