Chapter 1-3 Test Flashcards
What is matter?
Anything that occupies space and has mass (forms of energy aren’t matter)
What is a pure substance?
Uniform chemical composition
What is a mixture?
Composed of two or more pure substances and may or may not have uniform composition
Two different types of pure substances
Element and compound
What is an element?
Cannot be broken down
Different kinds of elements
Metals, metalloids, nonmetals
What is a compound?
Composed of 2 or more elements combine in definite proportions
Metal
Lustrous, malleable, ductile, conductor of heat and electricity, usually solid at room temperature
Nonmetal
Dull, brittle, insulator of heat and electricity, may be solid, liquid, gas, at room temperature
Metalloid
Has properties of both metal and nonmetal
Atom
Smallest unit of an element that retains the chemical properties of that element
Molecule
Smallest unit of a compound that retains the chemical properties of that compound
Different types of mixtures
Homogenous and heterogeneous
Homogeneous
Same composition throughout, dissolved, mixed properly
Heterogeneous
Don’t have uniform composition (ie potting soil)
Property
A characteristic that we can observe
Change
Process that changes the properties of a substance
Physical property
A characteristic we can observe
Qualitative physical property
Color, odor
Quantitative physical property
Mass, density
Physical change
A process in which no new substances are produced
Chemical property
A characteristic that can only be observed when a substance is converted
Density
D = m/v
Energy
Capacity to do work or transfer heat
Kinetic energy
Energy of motion
Potential energy
Energy possessed by an object because of its position
Exothermic process
Processes that release energy
Endothermic process
Processes that require energy input
Scientific method
Observation -> Hypothesis -> Experiment -> Conclusion (theory)
Scientific notation
Decimal to the right equals negative exponent, decimal to the left equals positive exponent
Laws of conservation of mass
Mass is not gained or lost in a chemical reaction
Law of definite proportions
A compound always has the same mass ratio of the elements that compose it
Dalton’s Atomic theory
All matter is composed of atoms, AL atoms of an element are identical in physical and chemical properties, atoms are not created or destroyed in reactions, atoms rearrange into new combinations, obeying the law of conservation of mass
Temp
Change in heat
Structure of an atom
Composed of subatomic particles and nucleus
Protons
Located in a tiny core at the center of the atom with a positive charge. Can count on right hand corner of element in periodic table
Neutrons
In nucleus, no charge. Can be counted by subtracting proton number from mass number
Electrons
Occupies empty space around nucleus, negative charge. Number is equal to proton number
Atomic number
Number of protons in an atom. Protons + neutrons
Isotope
An atom that contains a specific number of neutrons (will have number of protons from element)
Isotopic symbol
Ions
Differ from atoms in that they have a charge, the number of electrons do not equal protons
Cations
Positively charged ions, fewer electrons
Anions
Negatively charged, more electrons
Group or family
Elements in the same column behave similarly
Period
Horizontal row
Ionic compounds
Made of cation (the metal) and anion (the nonmetals)
Name of cation
Name of metal + “ion”