chemistry
mixtures can also be non-uniform (called ___)
heterogeneous
beach sand
heterogeneous mixture
salad dressing
heterogenous mixture
Is there a reaction between substances in mixtures?
no
Fine crystals of silver chloride are separated from a suspension of the crystals in water.
physical
Pure water freezes at 0°C.
physical
Salt substitute, potassium chloride, dissolves in water.
physical
Sugar crystals are separated from a sugar syrup by evaporation of water.
physical
The gas hydrogen sulfide smells like rotten eggs.
physical
iron filings are separated from sand by using a magnet
physical
a compound is always homogeneous
uniform
can mixtures be separated into their components by chemical or physical means?
yes
What does the metric prefix milli mean?
1/1000
What does the metric prefix kilo mean?
1000 time larger
Select the correct number of significant figures for 0.0230.
3
heterogeneous mixture
A heterogeneous mixture is a mixture where the components of the mixture are not uniform or have localized regions with different properties. Different samples from the mixture are not identical to each other.
substance
A solution is a homogeneous mixture of two or more substances.
over 100 existing elements are listed and classified on the
Periodic Table
solution
a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent.
The concept of ____ indicates how close the experimental answer is to the true value.
accuracy
pure substance containing only one kind of
atom
a pure substance containing 2 or more kinds of
atoms
an element _____ be separated into simpler materials (except during nuclear reactions)
cannot
compounds ____ be separated by physical means. Separating a compound requires a chemical change
cannot
Copper is produced when zinc metal is placed in a solution of copper(II) sulfate, a compound.
chemical
Fine steel wool (Fe) can be burned in air.
chemical
Seashells, calcium carbonate, fizz when immersed in vinegar.
chemical
Sodium metal is obtained from the substance sodium chloride.
chemical
the atoms are ____ combined in some way. Often (but not always) they come together to form groups of atoms called molecules
chemically
the properties of a mixture are similar to the properties of its ___
components
carbon dioxide
compound
magnesium oxide
compound
water
compound
mixture
different things mixed together
two or more ___ or ___ NOT chemically combined
elements, compounds
an element is always uniform all the way through
homogeneous
mixtures can be uniform (called ___) and are known as solutions
homogeneous
Classify the following as homogenous mixtures, heterogenous mixtures, elements or compounds.
homogeneous mixture
homogeneous mixture
homogeneous mixture is a mixture where the components that make up the mixture are uniformly distributed throughout the mixture. The composition of the mixture is the same throughout.
The concept of ____ indicates the ability of a person to measure consistently
precision
seawater
solution
fluorine
substance
sulfur
substance