Competency 1.0 The Structure and Behavior of Matter Flashcards
Mass
A measure of the amount of matter in an object
How is mass measured?
The units of mass is measured in 2 different ways
1. In SI units it is measured in kilograms
- In English units it is measured in pounds (not to be confused with weight)
Weight
The measure of the force of gravity
not to be confused with mass!
What is a physical property of a substance?
- It’s density
- Color
- Hardness
- Viscosity
- Resistivity
- Solubility
- Ductility
What is density?
The mass of an object made of a substance divided by it volume
Equation: D =m/V
Chemical properties
Describes the ability of substances to be changed into new substances
Ex: Iron + air = rust (a chemical change as iron has different properties from rust)
Phase of matter
Refers to its three possible states
- Solid (has a definite shape and volume)
- Liquid (has a definite volume but takes shape of its container)
- Gas (will spread to occupy the entire space it is in)
Kinetic Theory of Matter
States that all matter consists of atoms or molecules in a state of constant motion
What is a plasma?
A partially ionized gas in which some of the electrons are not bound to any atoms or molecules.
They are the most common form of matter in the universe because stars are composed of plasmas.
They are electrically conductive.
What are the 4 physical properties of a gas?
- Temperature (T)
- Volume (V)
- Mass (n)
- Pressure (P)
Temperature
Is measured by a thermometer in either Fahrenheit or Celsius degrees
The SI unit for temperature is “kelvin” (k)
The average kinetic energy of atoms or molecules in a gas determines its temperature.
The lowest unit of temperature is 0kelvin and = an absence of molecular motion
Mass
Is measured in moles (n) which is the number of molecules in a gas
Mass is expressed and calculated in terms of Avogadro’s number: 1n = 6.02 x 10²³
What is SI?
The international system of units maintained by the International Bureau of Weights and Measures in Severes, France
Also known as the Metric System
Pressure
The pressure of a gas is a measure of the force it exerts on the wall of a container divided by the area of the wall.
Equation: P= F/A
The SI unit of force = Newton
The SI unit of pressure = Pascal
The Ideal Gas Law or Combined Gas Law
Pg.18
A combination of Boyles law, Charles Law and Gay-Lussacs Law
Represented by this equation:
P¹V¹ P²V²
−−− = −−−−
T² T²
Boyles Law
Pg.18
The temperature is constant and the pressure and volume are inversely related. If the volume decreases the pressure of the gas will increase because the particles will collide more frequently with each other.
Charles Law
Pg.18
Pressure is constant and volume and temperature are directly related. If the temperature increases the kinetic energy of the particles increases causing the volume to increase.
Ex. A balloon will get bigger when hotter and smaller when colder.
Gay-Lussacs Law
Pg.18
The volume is constant and amount is the same when you heat the gas the pressure will increase. Ex. Gas inside a metal container:The temperature will cause the particles to move faster inside the container and since the container is constant and can’t be stretched the particles will hit the side with greater force causing an increase in pressure.
John Daltons Atomic Model
Pg.18
Made from observations in 1780s
- Matter is made up of atoms
- Atoms of an element are similar to each other
- Atoms of different elements are different from each other
- Atoms combine with each other to form new kinds of compounds
William Crookes
Pg.18
In 1870s created “cathode rays” in a vacuum tube by connecting a high voltage battery to an anode and cathode
J. J. Thomson
Pg. 18
In 1896 discovered the electron
He also developed the “plum pudding” model of the atom. In this model the atom consists of electrons equally mixed in a sphere of positive material.
Plums= electrons pudding = positively charged matter
Ernest Rutherfords Atomic Model
Pg. 19
- Most of an atom consists of empty space
- At the center of an atom is the nucleus that contains most of the mass and all of the positive charge of the atom.
- The region of the space outside the nucleus is occupied by electrons
- The atom is neutral because the positive charge on the nucleus equals sum of the negative charges on the electrons.
Niels Bohr Model of the Atom
Pg.19
In 1913 based on discoveries in quantum mechanics
- Electrons orbit the nucleus, but only in discrete orbits or energy levels
- Electrons don’t emit radiation when orbiting the nucleus
- When an electron moves from an outer orbit or higher energy level to an inner orbit or lower energy level, it emits a photon with an energy equal to the energy difference.
Compound
Pg.19
A thing that is composed of two or more elements that have been chemically combined
Ex: water = hydrogen + oxygen
Element
Pg.19
A substance that cannot be broken down into other substances
There are currently 118 elements on the periodic table built up by increasing the number of protons and neutrons in the nucleus.
Molecule
Pg.20
The smallest particle of a substance that can exist independently and has all the properties of that substance.
Ex: a water molecule = 2 hydrogen atoms and 1 oxygen atom (chemical formula = H2O)
Mixture
Pg.20
A combination of two or more substances in which the substances keep their own properties. Unlike a compound, they can be separated again by physical means.
Ex: a fruit salad
The four common compounds
Pg.20
- Acids
- Bases
- Salts
- Oxides
They are classified according to their characteristics
Acids
Pg.20
Contain hydrogen ions (H+), they also have a sour taste
4 common acids:
NAME FORMULA USE
1. Sulfuric Acid H₂SO₄ Fertilizers, explosives
2. Nitric Acid HNO₃ Medicines, alcohol
3. Carbonic Acid H₂CO₃ Soft drinks
4. Acetic Acid HC₂H₃O₂ plastics, film, rubber