Science 8 Spring Final Studying

Deposition

The change from a gas to a solid

Melting

The change from a solid to a liquid

Liquid

Matter that has a definite volume but not shape

Freezing

The change from a liquid to a solid

Physical Property

A characteristic of a substance that can be observed and does not change the identity of the substance

Plasma

Extremely high energy matter, the most common matter in the universe

Specific Gravity

The ratio comparing the density of a substance to the density of water

Density

Mass divided by volume

Chemical Property

A characteristic determined by the chemical make-up and bonding of a substance

Crystalline Solid

Solid particles that are arranged in a regular repeating patterns

Chemical Change

Process in which a substance becomes a new substance

Condensation

The change from a gas to a liquid

Gas

Matter with no definite shape or volume

Sublimation

Change from a solid to a gas

Buoyant Force

An upward force found in gases and liquids

Viscosity

The resistance of a liquid to flow

Physical Change

A change in which the substance changes form but keeps its same chemical composition

Amorphous Solid

Solid particles lacking in long-range atomic order

Solid

Matter that has a definite shape and volume

Vaporization

Change from a liquid to a gas

Thermal Energy

The sum of the kinetic energy of the molecule of a substance

Heat

Thermal energy that is transferred due to a difference in temperature.

Temperature

The average kinetic energy of a substance

Conduction

The transfer of heat energy by objects touching and particle colliding

Convection

The transfer of heat through fluids where hot fluids rise, while cool fluids sink

Radiation

The transfer of heat through empty space

Conductor

A material through which heat does flow easily

Insulator

A material through which heat does not flow easily

Exothermic

A process that gives off heat to the surroundings

Endothermic

A process that absorbs heat to the surroundings

Fahrenheit Scale

Temperature scale with 180 degrees between freezing and boiling

Celcius Scale

The temperature scale with 100 degrees
between freezing and boiling

Kelvin Scale

An absolute thermodynamic temperature scale where 0K is absolute zero

Absolute Zero

The lowest temperature that is theoretically possible where all thermal motion ceases.

Specific Heat

The amount of heat to raise 1 kg of a substance 1 ℃

Thermometer

An instrument used to measure the temperature of an object temperature

Thermal Equilibrium

The state where two or more objects stop transferring thermal energy, resulting in them having the same temperature

What is the movement of thermal energy?

Thermal energy will flow from the warmer substance to the cooler substance until both substances reach the same temperature, called thermal equilibrium

What happens to the molecules when thermal energy is increased?

The molecules speed up

What happens to the molecules when thermal energy is decreased?

The molecules slowed down

Examples of conduction

hand holding an ice cube, touching a hot pan, cooking eggs in a pan

Examples of convection

convection oven, boiling water, hot air balloon

Examples of radiation

the sun, campfire, heat lamps, candle warmers, heating food in a microwave

Examples of Insulators

wood, cork, plastic foam, vacuum layers

Examples of Conductors

copper, steel, metal, aluminum

Thermal energy formula

Q = mx∆TxCp

Formula for converting from Celsius to Kelvin

C = K-273.15

Formula for converting from Kelvin to Celsius

K = C+273.15

Units that measure thermal energy

Joules, calories, kilocalories

Units for specific heat

J/g×°C, J/kg×°C, J/kg×K, cal/g×°C

Examples of materials with a high specific heat

Water (4.184 J/g°C)

Examples of materials with a low specific heat

metal, sand, ceramic, glass

What phase of matter is conduction most apparent?

Solids

What is 273.15K in Celsius?

0°C

What temperature is absolute zero?

OK

When the temperature decreases of a substance decreases, the kinetic energy _

also decreases

Atoms

The smallest part of an element that can still be identified as that element.

Protons

positively charged particles found in the nucleus of the atom

Neutrons

neutral particles found in the nucleus of an atom

Electrons

negatively charged particles found outside of the atom's nucleus

Electron Cloud

contains electrons

Nucleus

the center core of an atom

Atomic Number

represents the number of protons in the nucleus of an atom, and it identifies the element

Atomic Mass

the total number of protons and neutrons in an atom

Isotope

an atom of an element with the same number of protons, but a different number of neutrons

Group

Columns in the periodic table that organize the elements by their properties

Period

Rows in the periodic table that organize the elements by their energy levels

Elements

pure substances that are made of only one kind of atom and retain their properties even when put through a phase change

Compounds

a substance made of 2 or more elements that are chemically bonded to each other

Ions

an atom that is no longer electrically neutral because it has lost or gained valence electrons

Ionic Bonds

attraction between positively and negatively charged ions (usually between metals and non-metals)

Covalent Bonds

a bond that involves the sharing of electrons to form electron pairs between atoms (usually between non-metals and non-metals)

Metallic Bonds

a bond formed when many metal atoms share their pooled valence electrons

How is the periodic table arranged?

In periods (rows) and groups (columns) by elements' characteristics by atomic number

Why is the periodic table arranged?

Because Mendeleev noticed that elements with similar properties occurred periodically

Who organized the periodic table?

Dmitri Mendeleev

What makes a positive and negative ion?

Gaining or losing an electron

What are the different types of chemical bonds?

ionic bonds, covalent bonds, and metallic bonds

What are the families of the periodic table?

Alkali metals, alkaline earth metals, transition metals, boron family, carbon family, nitrogen family, oxygen family, halogens, noble gases

Reactivity of alkali metals

extremely reactive (1 valence electron)

Reactivity of alkaline earth metals

highly reactive (2 valence electrons)

Reactivity of transition metals

varied reactive

Reactivity of the boron family

less reactive (3 valence electrons)

Reactivity of the carbon family

less reactive (4 valence electrons)

Reactivity of the nitrogen family

less reactive (5 valence electrons)

Reactivity of the oxygen family

more reactive (6 valence electrons)

Reactivity of halogens

very reactive (7 valence electrons)

Reactivity of noble gases

unreactive (8 valence electrons)

Properties of metals

(left side of periodic table) They are shiny, malleable (bendable), ductile, excellent conductors, have a high melting point.

Properties of non-metals

(right side of periodic table) They are dull, brittle, poor conductors, have low melting points.

Examples of metals

Gold, copper, aluminum

Examples of non-metals

Oxygen, carbon, chlorine

compression

squeezing a group of particles in a wave

mechanical wave

a transverse or compressional wave that can only travle through matter

medium

the matter through which a wave transfers energy

transverse waves

a mechanical wave in which matter moves at right angles to the wave directoin

electromagnetic wave

a wave that doesn't require matter to transfer energy

longitudinal wave

a wave in which matter moves back and forth in the direction the wave is moving

rarefraction

a region of spread-out particles in a wave

amplitude

the distance from the crest or trough of a wave to the rest position