Science Flashcards
Small particles, building blocks of matter
Atoms
Physical properties that depend on size, vary depending on how much matter is in a sample
Size Dependent
Do not depend on the amount of matter present, same for both small and large sample
Size Independent
Mass per unit volume of a substance, size independent
Density
Anything that has mass and takes up space
Matter
Solution
Homogeneous mixture, substance present in the largest amount is called the solvent, samples will have the same amount of each substance
Matter that can vary in composition, combinations of two or more substances that are physically blended together, can be separated by physical methods
Mixture
Substance containing atoms of two or more different elements chemically bonded together.
Compound
Physical properties
Characteristics of matter that you can observe or measure without changing the identity of matter.
State of matter, size dependent and size independent
Characteristics of matter that can be observed as it changes to a different type of matter
Chemical properties
Change in size, shape, form or state in which the matters identity stays the same
Physical change
Chemical change
Change in matter which substances that make up the matter and change into new substances with new physical and chemical properties
Chemical reaction
Often called chemical changes
If particles collide with enough force, bonded atoms can break apart
When they rearrange and bond, new substances can be formed
Amount of substance in a volume
Concentration
Substances that are evenly mixed, known as a solution
Homogeneous mixture
Heterogeneous mixture
Not evenly mixed. Samples not the same
Factors that affect size of a reaction
Temperature (higher=faster) Concentration (higher=faster) Surface area (more=faster)
Matter with a definite volume but not definite shape
Liquids
Solids
Definite matter and shape, strong attractive forces.
Crystalline- repeating order
Morphis- Random
No definite shape or volume, particles are far apart and move freely, weak attractive forces
Gases
High energy matter consigns of positive, negative charged particles
Most common state of matter in space
Plasma
Uneven forces acting on the particles on surface of a liquid
Surface tension
Condensation
Gas->Liquid
Gas loses thermal energy
Gas-> Liquid, skips the solid stage
Thermal energy removed
Deposition
Sublimation
Solid-> gas
Skipping liquid stage
Solid to liquid
Melting
Liquid to solid
Freezing
Liquid to gas
Boiling
Liquid surface to gas
Evaporation
How do energy particle change state of matter?
When energy is added, it means particles are moving faster (warmer), or there is more kinetic energy
How does a dense ship float on water?
It is filled with gas
Kinetic energy
Energy due to motion
Faster=more energy
Potential energy
Stored energy due to interactions between particles or objects
Boyles law
Pressure of gas increases if the volume decreases and pressure of a gas decreases if the volume increases. Temperature is constant
Low temp=high volume
Charles’s law
Volume of gas increases with increasing temperature. Pressure is constant
Low pressure=high volume
Measure of the average kinetic energy of all particles in an object
Temperature
Pressure
When particles collide with their container, pressure results
Amount of force applied per unit of area
Sum of the number of protons and neutrons in an atom
Mass number
Aristotle atomic theory
No empty space; fire, water, air and earth
Democritus atomic theory
Atoms are solid objects that cannot be divided created or destroyed, constantly moving in empty space, much like today’s modern theory
Daltons atomic theory
All matter is made of atoms that can’t be divided, created or destroyed, during a chemical reaction atoms of one element can’t be converted to atoms of another element, atoms combine in specific ratios,
Thomson atomic theory
Discovered electrons, model contained both positive and negative electrons (plum pudding model)
Rutherford
Concluded most of an atoms mass and positive charge was in the nucleus
Protons
Symbol: p, positive one charge, located in the nucleus
Neutral particle, in the nucleus, symbol: n,
Neutrons
Symbol:-e, negative one charge, around the nucleus in an electron cloud
Electron
Nucleus
Where most of an atoms mass and positive charge is concentrated
Alpha decay
Made of 2 proton and 2 neutron (alpha particle)
Atomic number decreases by two
Neutron in an atom changes into a proton and becomes part of the nucleus, releases a high energy electron
Atomic number increased by 1
Beta decay
Gamma decay
Contain energy (gamma ray) doesn’t change atomic number of element
Ionic bond
Attraction between positive and negative charged ions in an ionic compound. Nonmetal ion with metal ions
Solid crystals, high melting and boiling points, dissolve in water, salt (Na+ Cl-)
Nonmetal atoms with nonmetal atoms. Gas, liquid, or solid
Low melting and boiling points, don’t dissolve in water, poor conductors, don’t dissolve in water
(Dull)
(Water)
Covalent bonds
Molecules
Group of atoms held together by covalent bonding
Acts as an independent unit
Metal ions with metal ions
Solid, high melting and boiling points, do not dissolve, conductors, shiny, sea of electrons
Metallic bond
Polar molecule
Has a partial negative and partial positive charge due to unequal sharing of electrons
No longer electrically neutral because of lost or gained electrons
Ions
How many valence in the first two clouds?
2(first level)+8(second level)=10
How many valence are needed for a stable atom
8
Bohr
Proposed electrons move in circular orbits (energy level) around the nucleus
Closer=less energy
Henry bacqurerel
Discovered radiation
Studied mineral that when left in sunlight gave of energy
What can differ between atoms of different elements
Number of protons, neutrons, and electrons
Why are scientist having trouble describing an atom?
Too small
Water
Covalent
Salt
Ionic
Dot diagram
Shows atoms and valence
Shows atoms and lines, lines represent one shared pair of electron
Structural formula
Balls represent atoms, sticks represent bonds, used this who bind and angles
Ball and stick model
Spheres represent atoms, 3-D arrangement of atoms
Space filling model
Periodic
Repeating pattern
Period
Rows
Group
Column
Atomic number
Number of protons in the nucleus, increases from left to right
Group one
Alkali metals, react aggressively, lowest density
Alkaline earth metals
Group two, react with other elements, low density
Groups 3-12, metals, good building materials
Transition elements
Halogens
Group 17, racy with metal and form salt
Noble gases
Group 18, stable
Semi conductors
Metalloids, only elements that are semi conductors
