Chemistry Flashcards
what is the particle model of matter?
a model that describes the arrangement and movement of particles in a substance.
what is the particle model of matter used for?
To explain the physical properties of solids, liquids, and gasses.
What is matter?
anything that has mass, volume, and takes up space
What do atoms come together to form?
molecules
what does an atom contain in its nucleus?
protons and neutrons
what are the different states of matter?
solid, liquid, and gas
what are some characteristics of matter in the solid state?
- tightly packed
- vibrate
- retains a fixed volume and shape
- little free space between particles
- does not flow
- particles can not move or slide past each other
- low energy
- strong attractive forces
what are some characteristics of matter in the liquid state?
- close together
- vibrate
- move about and slide past each other
- assumes the shape of the par of its container that it
occupies - flows easily
- little free space between particles
what are some characteristics of matter in the gas state?
- weak attractive forces
- lots of energy
- vibrate
- move freely at high speeds
- assume the shape and volume of its container
- flows easily
- compressible
- particles can move past each other
- lots of free space between particles
what is a pure substance?
a single substance on its own
what are mixtures?
two or more substances that are not chemically combined
what are the two types of mixtures?
heterogeneous and homogenous
what is a homogenous mixture?
the composition is uniform throughout the mixture
what is a heterogeneous mixture?
a non-uniform mixture of constituent parts
what is a suspension?
a heterogeneous mixture that contains solid particles sufficiently large for sedimentation
what is a colloid?
a colloid is a phase-separated mixture in which one substance of microscopically dispersed insoluble to soluble particles is suspended throughout another substance
what is an emulsion?
a mixture of two or more liquids that are normally immiscible owing to liquid-liquid phase separation
what is the difference between quantitative and qualitative observations?
quantitative observations are properties that have numerical characteristics, whereas qualitative observations are properties that can be observed but are generally not measured with a numeric result
what is the difference between a physical property and a chemical property?
a physical property is a characteristic of a substance that can be observed or measured without changing its identity whereas a chemical property is a substances ability to undergo a chemical change
what is the difference between physical and chemical changes (reactions)?
In a physical change, the appearance or form of the matter changes but the kind of matter in the substance does not. They can be reversed. In chemical change the kind of matter changes and at least one new substance with new properties. This cannot be reversed.
what are some indicators of a chemical change?
- color change
- formation of a precipitate
- formation of gas
- odor change
- temperature change
- can not be reversed
- bubbles
what is reaction rate and how is it typically determined?
a measure of how fast a reaction occurs which is typically determined by assessing the amount of products released over a given period of time
what is galvanization?
a process that treats a metal to prevent rusting
list 4 things that can change reaction rate and how each of them affects the speed at which the reaction occurs
- agitation (increased agitation speeds up reactions rate)
- temperature (higher temperatures speed up reaction rate)
- reactant concentration (higher concentrations speed up reaction rate)
- surface area (reactants with a larger surface area exposed will speed up the reaction rate)
what is a catalyst?
something that is added to the reaction to speed up the reaction rate. It is not consumed or changed during the reaction, nor does it change the amount of product that results.
what is a law vs. a theory?
a law is used to summarize a scientific observation whereas a theory is the explanation of why an observation happens.
what is an atom?
atoms are the building blocks of matter and can be broken down into three types of subatomic particles:
- protons (positively charged particles found within the nucleus)
- neutrons (neutral particles found within the nucleus)
- electrons (negatively charged particles that orbit the nucleous
how was each atomic model developed?
each past model was developed on a set of observations that are eventually disproved and altered to fit a new set of observations
list the five atomic models in order of creation
daltons billiard balls, Thompsons plum pudding model, rutherfords planetary model, BHORS atomic model, quantum model
What is a neutron?
neutral particles found within the nucleus
what is an electron?
negatively charged particles that orbit the nucleus
what is a proton?
positively charged particles found within the nucleus
how do you know how many protons are in an atom’s nucleus?
based on the elements atomic number
how do you know how many electrons an atom has?
the number of electrons is equal to the number of protons within the nucleus, meaning you can determine the number of electrons based on the element’s atomic number.