Chapter 2: Matter & Energy
This is a form of matter that has a definite shape and volume
Solid
This is a quantity that includes both a number and a unit
Measurement
This is a positively charged subatomic particle that is present in all atoms.
Proton
what is the charge of an electron?
Negative
Is a horizontal row of the periodic table
Period
This is a substance that is present at the start of a chemical reaction
Reactant
This is a system of measurement based on the metric system
International System of Units
Is the tiny, dense, central core of the atom and is composed of protons and neutrons.
Nucleus
where are the electrons located in an atom?
Around the nucleus of an atom
This is a vertical column of the periodic table.
Group
This is a mixture in which the composition is uniform throughout the mixture.
Homogeneous mixture
This is a technique that uses the units (dimensions) of the measurement in order to correctly solve problems
Dimensional analysis
This states that during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants.
Law of conservation of mass
How many electrons can the first energy level hold?
2 electrons
This is an element that is a good conductor of heat and electricity.
Metal
This is a process that occurs when one or more substances are changed into one or more new substances
Chemical reaction
This is a measure of how close a measurement is to the correct or accepted value of the quantity being measured.
Accuracy
This states that a given chemical compound always contains the same elements in the exact same proportions by mass.
Law of definite proportions
what is the significance of valence electrons?
Valence electrons are the outermost electrons of an atom.
Is an element that is generally a poor conductor of heat and electricity.
Nonmetal
This is a characteristic of a substance that can be observed or measured without changing the identity of a substance.
Physical Property
Is the absolute value of the error divided by the accepted value and multiplied by 100%.
Percent error
Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.
Law of multiple proportions.
How does the quantum mechanical model describe the position of electrons?
Instead of fixed orbits, the quantum mechanical model describes electrons as existing orbitals.
This is a way of arranging the elements in order of their atomic numbers so that elements with similar properties appear in the same vertical column or group.
The periodic table