Chemistry Test1

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Which type of mixture contains multiple phases?
Which type consists of only a single phase?
Heterogenous mixtures
Homogenous mixtures
List four observations that may indicate a chemical change has occurred in a substance.
Formation of a gas
Formation of a precipitate
Liberation of absorption of heat, light, or some other form of energy.
A distinct change in color.
Does the consumation of food involve physical changes or chemical changes?
its both physical and chemical. when you chew your food its physical but when your food gets digested your stomach dissolves it causing it to be a chemical reaction.
Classify the following changes as chemical or physical.
cutting of meat-physical
leaves changing color in autumn-chemical
baking a cake-physical/chemical
magnetizing a nail-physical
cutting the grass-physical
lighting a candle- chemical
From what are the symbols for the elements potassium and sodium derived?
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Which of the three basic subatomic particles that compose an atom is least massive?
electrons..
What type of smaller particles is thought to make up protons and neutrons?
electrons.
Distinguish between atomic number and mass number.
Atomic Number- the number of protons in the nucleus.
Mass Number- the sum of the number of protons and the number of neutrons in a nucleus.
What is an isotope?
atoms of the same element that differ in their mass numbers.
What is an ion? What determines whether an ion is a cation or an anion?
Ion- an atom or molecule that is electrically charged because it has a diffrent number of electrons than protons.
if it has more electrons than protons, the ion has an excess of negative charge; it is thus negatively charged and its an (Anion). If the ion has fewer electrons than protons, there is an excess of positive charge; a positively charged ion is called a (Cation).
What unit is used to measure atomic mass? Upon what standard is this unit based?
mass spectrometer, atomic mass units .