55 terms

Physical Science 9 weeks test

a representation of an object or event that can be studied to understand the real object or event
the application of science for practical uses. Advances in science depend on this:
observing, studying, and experimenting to find the nature of things
critical thinking
when you approach a problem by asking questions, making observations, and using logic to make a decision
scientific methods
general ways to help organize your thinking about questions
a process in nature that can be tested by repeated experiments
a factor that changes in an experiment in order to test a hypothesis
a measure of the amount of matter in an object
dependent variable
the observed result of the variable being manipulated or changed
a description of how close a measurement is to the true value of the quantity measured
independent variable
the variable representing the value being manipulated or changed
the exactness of a measurement
an explanation of how a natural process works
a measure of the gravitational force exertedd on an object
a substance made up of atoms of two or more different elements joined by chemical bonds
the physical form of a substance
melting point
the temperature and pressure at which a solid becomes a liquid
chemical change
a change that occurs when one or more substances change into entirely new substances with different properties
anything that has mass and takes up space
a substance that cannot be separated or broken down into simpler substances by chemical means
a combination of two or more substances that are not chemically combined
the ratio of the mass of a substance to the volume of the substance
boiling point
the temperature and pressure at which a liquid becomes a gas
the smallest unit of an element that maintains the chemical properties of that element
physical properties
characteristics tha can be observed without changing the identity of the substance
physical change
a change of matter from one form to another without a change in chemical properties
when oxygen and hydrogen atoms combine to form a molecule
a nonsolid state of matter in which the atoms or molecules are free to move past each other
law of conservation of mass
the idea that mass cannot be created or destroyed
hydraulic devices
the use of liquids to transmit pressure form one point to another
the amount of force exerted per unit area of a surface
a state of matter that consists of free-moving ions and electrons that does not have definite shape or volume
gas laws
the laws that state the mathematical relationships between the volume, temperature, pressure, and quantity of as
condensation point
the temperature at which a gas becomes a liquid
the resistance of a gas or liquid to flow
buoyant force
the upward force that keeps an object immersed in or floating on a fluid
the capacity to do work
the SI unit for pressure
a measure of how hot or cold something is; specifically, a measure of the average kinetic energy of the particles in an object
kinetic energy
the energy of motion
negatively charged particles inside the atom
an atom's central region, which is made up of protons and neutrons
law of definite proportions
this states that a chemical compound always contains the same elemetns in exactly the same proportions by weight or mass. an example of this is water.
a region in an atom where there is a high probability of finding electrons
protons and neutrons
two subatomic particles that are almost identical in size and mass
ground state
the lowest state of energy of an electron
electrons gain energy by absorbing a particle of light called an ___.
electric force
positive and negative charges attract each other with a force known as ___.
Which orbital is sphere-shaped?
a charged atom
mass number
the sum of the number of protons and neutrons in the nucleus of an atom
an atom that has the same number of protons but a defferent number of neutrons relative to other atoms of the same element
molar mass
the mass in grams of one mole of a substance
atomic number
the number of protons in the nucleus of an atom
in the modern atomic theory, electorns can be found only in certain ____ levels.