ch1 Flashcards
Metric system
- Mass is represented in gram (g), the length in meter (m) , and volume in liter (L)
English system -
Weight is measured by the unit of pound (lb) , the length by the unit of yard (yd), and the volume by the unit of gallon (gal)
SI system
(International System). Based on the metric system
Metric system
? mm = 1 cm
? cm = 1 m
?m = 1 km
10 mm = 1 cm
100 cm = 1 m
1000m = 1 km
The total number of digits used to express such a measurement is called the number of ..
significant figures
how many significant figures in exact number?
have an infinite number of significant figures
what is an exact number?
Determined by counting and not by using a measuring device
Zeroes in the middle (significant or not)?
significant
Zeroes at the beginning of a number (significant or not)?
not significant
Zeroes at the end of a number( significant or not)
significant
Mass is
is a measure of amount of matter in an object.
Volume is
is the amount of space occupied by an object
density is
an amount of mass is a given space (density=mass/volume)
Chemistry : is the study of
matter
Chemistry
Its chemical and physical properties.
Chemical and physical changes it undergoes.
Energy changes of these processes.
matter is
Anything that occupies space and has mass
matter Exists in three states
Solid
Liquid
Gas
properties of a solid
Rigid
Fixed volume and shape
Slightly compressible
properties of a solid
Rigid
Fixed volume and shape
Slightly compressible
Properties of a Liquid
Definite volume
No specific shape (Assumes the shape of its container)
Slightly compressible
Properties of a Gas
-No fixed volume or shape
(Takes on the shape and volume of its container)
-Highly compressible (Relatively easy to decrease the volume of a gas )
The conversion of a substance from one state into another is known as
change of state.
processes from solid to liquid
processes from liquid to gas
melting
evaporation
gas to liquid called..
liquid to solid called..
condensation
freezing
Physical Properties can be
- measured or obtained without changing the composition of the material. like to separate a mixture into pure compounds, but it will not break compounds into elements.
- no chemical changes
- reversible
examples of physical properties
mass- density- texture- volume- magnetism- length- color
what are intensive and extensive properties?
Intensive Property : Independent of the quantity of substance (Ex: color, hardness, melting, boiling point, density)
Extensive Property: Depends on the quantity of the substance (Ex: mass, volume, length, weight)
Separating mixture into pure compounds , changing physical properties by:
filtration - distillation - chromatography
Chemical properties
-undergo chemical changes
examples of chemical changes
flammability toxicity rust with oxygen react with finger and water radioactivity sensitivity to light
chemical changes are
- irreversible
- a given substance becomes a new substance with different properties and composition
chemical reaction
is a process of rearranging, replacing, or adding atoms to generate a new substance
Pure Substance:
Involves one component.
Sugar and water are pure substances.
A pure substance can be a 1chemical compound or 1 element
do pure substance can decompose to other substance?
no they can’t decompose to other substances
atom
is the smallest particle of an element that have the chemical properties of an element
molecule
smallest unit of a compound, 2 or more atoms connected together
it can be the same atom like O2
Chemical Element:
substancewhose atoms all have the same number of protons
Chemical Compounds:
are composed of atoms chemically bonded to each other in fixed ratios and can be decomposed to those atoms
matter
composed of tiny particles called atom
mixture
more than one substance
types of mixture
Homogeneous mixture (solution) and Heterogeneous mixture
Heterogeneous mixture:
have many phases like sand in water - oil in water , non-uniform composition
Homogeneous Mixture
have on phase , uniform composition like water and alcohol
