Chemistry Unit 2

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What is the name for two atoms (same element) with a different number of neutrons?
What is the name for the number of protons in an element?
Atomic Number
How is the charge of an atom determined?
protons and electrons
What is Democritus known for?
He was the first to come up with the idea of atoms
Who created the Solid Sphere Model?
John Dalton
Who created the plum pudding/chocolate chip cookie model?
JJ Thomson
What experiment is Ernest Rutherford known for?
The Gold foil experiment
What was the gold foil experiment done to prove?
Atoms are mostly empty space and have a nucleus
Who created the Planetary model?
Niels Bohr
Who discovered neutrons?
James Chadwick
Who discovered electrons?
JJ Thomson
What is the law of conservation of mass?
matter cannot be created or destroyed
What is the 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
What is the law of multiple proportions?
If two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers.
What does AMU stand for?
atomic mass unit
What is a proton's charge?
positive (+1)
what is an electrons charge?
Negative (-1)
What is a neutrons charge?
neutral (0)
What is the definition of an atom?
The smallest particle of an element that retains chemical properties
What is the minimum amount of protons in the nucleus?
Can the amount of protons vary between different forms of the SAME element?
What is a quark?
An elementary particle that makes up atoms. (Specifically protons and neutrons)
What makes up a proton? (Think types of quarks and what connects them)
2 up quarks, 1 down quark, and gluons
Are electrons made of quarks?
What subatomic particles make up mass number?
protons and neutrons
What is an allotrope?
Different forms of the same element
What is an ion?
An atom that has gained or lost electrons
What is a cation?
positively charged ion (loses electrons)
What is an anion?
negatively charged ion (gains electrons)
What is average atomic mass?
A weighted average of the atomic masses of all isotope of a given element
What is the value of Avogadro's Constant? (It is also equal to one mole)
What is molar mass?
the mass of one mole of a substance
Which elements' molar mass rounds up to a whole number?
Chromium (Cr), Oxygen (O), and Fluorine (F)
1 unit of the following: Atoms, molecules, formula units, 22.4 L of gas at STP, and molar mass, are all equal to how many moles?
1 mole
What are the physical characteristics of Democritus's "Atomos"
The size of a grain of sand, indestructible, and indivisible
(True or false) All matter is made of atoms
(True or false) Atoms from different elements are different sizes
(True or false) Atoms can't be divided, created, or destroyed
(True or false) In reactions, atoms are combined, seperated, and/or rearranged
What subatomic particle is NOT part of the Nucleus?
What scientist thought that electrons move in an orbit?
Niels Bohr
Who discovered the Nuclear Model
Ernest Rutherford
What is the name of the current atom model?
Electron Cloud
Who discovered the Electron Cloud model?
Who did the oil drop experiment?
Robert Millikan
Who did the cathode ray experiment?
JJ Thomson
What are all 5 parts of John Dalton's atomic theory>
1. All matter is made of atoms 2. Atoms of different elements are different sizes 3. Atoms can't be divided, destoyed, or created. 4. Atoms of different elements combine to create chemical compounds 5. In reactions, atoms are combined, seperated, or rearranged.
What does STP stand for?
standard temperature and pressure