Exam Review Flashcards
What is matter?
It’s anything that has mass and takes up space.
What is an atom?
It’s the smallest unit of matter that has the properties of an element.
What is a compound?
A substance formed when two or more chemical elements are chemically bonded together.
What is a chemical property?
A change of a material’s properties that happen during or after a chemical reaction (basically any quality that can be seen only by changing a substance’s chemical identity)
What is a physical property?
Physical properties can be observed or measured without changing the composition of matter.
What is a physical change?
It is changes affecting the form of a chemical substance, but not its chemical composition.
What is an electron?
The smallest of the particles that make up an atom and they have a negative charge -1
What is a proton?
It’s a subatomic particle found in an atom and has a positive charge +1 (opposite of an electron)
What is a neutron?
It’s a subatomic particle found in the nucleus of atoms and is neutral (zero charge)
What is a molecule?
The smallest particle in a chemical element or compound that has the chemical properties.
What is a mixture?
A material made up of two or more different substances which are mixed but are not combined chemically.
What is ionization energy?
The amount of energy required to remove the most loosely bound electron (the valence electron) to form a cation.
What is a solution?
A homogeneous mixture composed of two or more substances
What is a concentration?
The number of molecules or ions in a given volume of a substance, expressed as mol/L (molarity).
What is a solute?
A substance dissolved in another substance, known as a solvent.
What is a solvent?
A substance that dissolves a solute resulting in a solution
What is a homogeneous mixture?
A mixture which has uniform composition and properties throughout. ie. oooooooo
What is a heterogeneous mixture?
A mixture in which the components can be seen ie. oooo0o0oo
What is a qualitative chemical analysis?
The identification of elements or grouping of elements present in a sample
What is a quantitative chemical analysis?
the determination of the absolute or relative abundance (usually expressed as a concentration) of one, a bunch or all substance(s) in a sample.
What is isoelectronic?
Refers to two atoms, ions or molecules that have the same electronic structure and same number of valence electrons.
What is the activity series?
A chart of metals listed in order of declining relative reactivity. The top metals are more reactive than the metals on the bottom.
What is the Law of Conservation of Mass?
This law states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. Mass of product in chemical reaction = mass of reactants.
What is the Law of Definite Proportions?
(Proust’s law) States that a chemical compound always contains its component elements in fixed ratio (by mass)
What is the Law of Constant Composition?
States that all samples of a chemical compound have the same elemental composition by mass
What is an atomic mass unit?
Unit of mass used to express atomic and molecular weights.
What is atomic mass?
Mass of an atom of a chemical element. The mass number is the total number of protons and neutrons combined
What is the molecular mass?
The mass of a molecule.
What is molar mass?
For ie. mmH2O=18.01 (16+2(1.01). It’s just the masses added up.
What is an ion?
An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
What is a cation?
A positively charged ion
What is an anion?
A negatively charged ion
What is an isotope?
The number of protons in an atom’s nucleus. For example, an atom with 6 protons must be carbon
What is electron affinity?
The amount of energy released or spent when an electron is added to a neutral atom or molecule
What is a pure substance?
Homogeneous substance that has consistent properties throughout the sample.
What is electronegativity?
Tendency of an atom to attract a bonding pair of electrons.
What are valance electrons?
The outside electrons are the most easily lost.
What is an ionic bond?
The complete transfer of valence electron(s) between a metal and non-metal
What is a covalent bond?
The sharing of electron pairs between two non metals.
What is a non polar covalent bond?
A type of chemical bond where two atoms share a pair of electrons with each other.
What is a polar covalent bond?
A type of chemical bond where a pair of electrons is unequally shared between two atoms.
What is effective nuclear charge?
The net positive charge experienced by an electron in a multi-electron atom.
What is the periodic law?
Properties of the elements are periodic functions of their atomic numbers. Also called Mendeleev’s law.
What is a period? A group?
Period is across the table. Group is down the table (which is a chemical family).
Group names on the periodic.
- Alkali metals
- Alkali earth metals
3-12. Transition metals
13-16. No approved names - Halogens
- Nobel gases
Contribution each scientist made on the structure of the atom:
Dalton, Thompson, Rutherford and Bohr.
Dalton- Proposed that all matter is composed of very small things which he called atoms.
Thompson- Proposed the plum pudding model of the atom that had no nucleus and is composed of + and - charged particles.
Rutherford- An atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths.
Bohr- Depicted the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus
Periodic trends: Increase or decrease?
- atomic radius
- 1st ionization energy
- electronegativity
Atomic radius
Across period= decrease
Down a group= increase
1st ionization energy
Across period= increase
Down a group= decrease
Electronegativity
Across period= increase
Down a group= decrease
What group of elements has the lowest electron affinity? Why?
Metals. Because metals lose electrons to become balanced rather than gain
