Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
What is macroscale?
|
things we can easily see with the naked eye or with the aid of a light microscope.
|
|
What is nanoscale?
|
The scale on which atoms and molecules exist (<10^-9 m)
|
|
What is a pure substance?
|
A sample of matter with a characteristic set of properties that does not change with further purification.
|
|
What are the two types of pure substances?
|
Elements and compounds
|
|
What is an element?
|
A pure substance that cannot be decomposed into simpler substances.
|
|
What is a compound?
|
A chemical combination of two or more elements.
|
|
What is the basic unit of an element?
|
The basic unit of an element is an atom.
|
|
What is the basic unit of a compound?
|
The basic unit of a compound is a molecule.
|
|
What elements exist as diatomic molecules?
|
H, N, O, F, Cl, Br, and I
|
|
What is a mixture?
|
A physical combination of two or more pure substances.
|
|
What are the two mixtures?
|
Homogeneous mixture(solution) and heterogeneous solution
|
|
What is a homogenous solution?
|
Evenly distributed throughout. ie) NaCl in water
milk |
|
What is a heterogenous solution?
|
Unevenly distributed throughout. ie) beach sand, orange juice, spoiled milk
|
|
What are physical properties?
|
Properties which can be measured without changing the compostition of the substance. These include:
melting point, boiling point, volume, hardness, density |
|
What two categories can physical properties be divided into?
|
Intensive and extensive
|
|
What are intensive physical properties?
|
Properties that are independent of the amount of substance present. ie) hardness, color
|
|
What are extensive physical properties?
|
Properties that depend on the amount of substance present. ie) mass, volume
|
|
What are chemical properties?
|
properties which describe the kinds of chemical reactions substances undergo. Chemical changes(reactions) produce new substances. ie) burning paper
|
|
What are physical changes?
|
Changes that occur without changing the compostition of the substance. ie) melting ice, boiling water
|
|
What are chemical changes?
|
Changes which result in a change in the chemical composition of a substance.
|
|
Kilo
|
10^3
|
|
Deci
|
10^-1
|
|
Centi
|
10^-2
|
|
Milli
|
10^-3
|
|
Micro
|
10^-6
|
|
Nano
|
10^-9
|
|
What is an isotope?
|
Atoms having the same number of protons, but different numbers of neutrons.
|
|
What are ions?
|
Atoms that have gained or lost electrons. Ions have a positive or negative charge.
|
|
What is a cation?
|
An ion with a positive charge
|
|
What is an anion?
|
An ion with a negative charge
|
|
How does metallic character increase on the periodic table?
|
Metallic character increases going down and to the left.
|
|
What did John Dalton do?
|
He proposed the first atomic model of matter that associated atoms with elements and molecules with compounds.
|
|
What did J. J. Thomson do?
|
He did experiments with cathode ray tubes and was able to measure the charge-to-mass ratio of elements but was unable to determine the charge of a single electron. He proposed the "Plum Pudding" model.
|
|
What did Robert Millikan do?
|
He was able to determine the charge of an electron with the oil drop experiment and the mass of an electron.
|
|
What did Ernest Rutherford do?
|
Used the gold foil experiment and discovered the atomic nucleus and proved the existence of protons.
|