Physical Science Semester II Exam Study Guide Flashcards

Flashcards for Physical Science Semester II Exam Study Guide KEY

Steps in using a fire extinguisher

Pull the pin, Aim the nozzle at the base of the fire, Squeeze the handle, Sweep side to side

When to wear safety goggles

When harmful chemicals, glass, or heat is being used

Chemical properties

Characteristic of a substance that indicates if it can undergo a chemical change.

Physical properties

Any characteristic you can observe of a substance that will NOT change its identity. (Examples include the substances appearance (color/size shape) behavior and characteristics (malleability, ductility, magnetic properties, conductivity) and physical changes (phase change/ cutting or changing the size or shape, dissolving it in water)

Pure substance

An element or compound and cannot be broken down or apart by physical means.

Mixture

A combination of two or more substances that are not chemically bound and can be physically separated or broken down.

Heterogeneous mixture

Unevenly mixed, and have parts that can be easily identified.

Homogeneous mixture

Evenly/uniformly mixed and particles cannot be identified easily.

Physical change

Phase change; does not change the substance.

Chemical change

Change in energy or gas formation; changes the substance

Five signs of a chemical change

Formation of a precipitate, Gas formation, Change in odor, Change in color, Change in energy

Potential Energy

Energy stored in a substance

Kinetic Energy

Moving energy in and between particles

Thermal Energy

The total amount of energy a substance has (sum of potential and kinetic)

Solids

Definite shape and volume. Substances only vibrate in place. Strong attractive forces holding them together. Low molecular movement and not much room to move. Low kinetic energy

Liquids

Definite volume, but no definite shape. Particles are less structured than a solid. Weaker attractive forces than a solid. little more room to move, but still close together. More molecular movement and energy than solids.

Gases

No definite volume or shape. None attractive forces; free flowing. High energy; more than liquids, less than plasma kinetic energy.

Plasma

Formed when particles collide with each other so hard that electrons are knocked off. made up of an equal number of positive ions and negative electrons; only charges attractive forces. Have the highest movement and kinetic energy, moves freely like gases

Bernoulli’s Principle

As velocity of a fluid is increases the pressure exerted by the fluid will decrease.

Pascal’s principle

Pressure applied to a fluid is transmitted throughout the fluid

Charles’s Law

The volume of a gas will increase with increasing temperature.

Kinetic Theory

An explanation of how matter behaves.

Evaporation

Evaporation can occur before boiling even happens. Evaporation also only occurs at the surface of the liquid.

Boiling point

Boiling occurs only when the pressure in the air is equal to the pressure in the fluid. It also occurs throughout the fluid.

Volume of an atom

There is a huge distance between the nucleus and the first electron. The electrons are spread out in the electron cloud as well.

Neutral charge of an atom

Atoms have an equal number of positively charged subatomic particles (protons) and negatively charged particles (electrons)

Positive charge of the nucleus

Protons and neutrons are located in the center of the atom. Protons have a positive charge and neutrons do not have a charge.

Negative charge of the electron cloud

Electrons occupy the electron cloud and are negative

Proton

Mass 1 amu charge 1 + location Nucleus, function identified the element (each element has a different number of protons—atomic number)

Neutron

Mass 1 amu charge 0 location Nucleus, function: To keep protons from pushing away from each other

Electron

Mass no mass charge 1 – location electron cloud, function: determines how reactive an element is. Elements bind by their electrons

Valence electrons

Electrons on the outermost energy level / orbital of an atom. These are the atoms that will bind to other elements forming compounds.

Metals

Take up most of the periodic table; Mailable, ductile; Lustrous; Good conductors of electricity and heat

Non-metals

On the right side of the periodic table; Neither mailable nor ductile; Dull; Bad conductors of electricity or heat

Dmitri Mendeleev

A scientist who organized the periodic table into columns and rows by mass and physical/chemical properties (today it has been revised to atomic number and chemical/physical properties)

Group

All elements in the same groups have similar properties; all elements in the same group ALSO have the same number of electrons in their outer energy level (Valence electrons) that can bind to other elements

Periods

The rows of the periodic table with increasing in atomic number from left to right. Elements in the same period also have the same number of energy levels / orbitals

Isotope

Atoms of the same element with a different number of neutrons.

Writing an isotope

Written with the name of the element first, followed by its mass. (EX. The isotope Boron-12 is the element boron with a mass of 12amu)

Covalent compounds

Between non-metals; Atoms share electrons to be stable (it takes too much energy to give or take electrons to be stable)

Ionic Compounds

Between metals and non-metals; Form from positive ions (cations = metals) and negative ions (anions = non-metals); Formed when opposite charges come together (think of the attractive forces of north and south of a magnet)

Metal ions

Positive charge (lose electrons to be stable)

Non-metal ions

Negative charge (gain electrons to be stable)

Synthesis reaction

Two or more substances combine to form another substance. Produces energy

Single displacement reaction

One element replaces another element in a compound in a chemical reaction to form a new element and new compound.

Double displacement reaction

Two compounds react and rearrange to form two new compounds.

Combustion reaction

A hydrocarbon reacts with oxygen to produce water, carbon dioxide, and energy in the form of heat and light. Mostly associated with burning. (note: oxygen cannot be attached to another element)

Decomposition reaction

A substances breaks down into two or more substances. Requires the use of heat, light, or electricity to occur

Catalyst

Used to speed up a reaction. Not part of the product and can be collected and reused

Inhibitor

Used to slow down a reaction. Not part of the product and can be collected and reused. Will not STOP a reaction

Exothermic reaction

Releases energy in the form of heat (gets warmer)

Endothermic Reactions

Absorbs energy in the form of heat (gets colder)