click below
click below
Normal Size Small Size show me how
Chapter 4 Vocab
Science
Term | Definition |
---|---|
Nucleus | Center of an atom. |
Proton | Positive electric charge. & It's inside the nucleus. |
Neutron | Have no electric charge. & It's inside the nucleus. |
Electron | Negatively charged subatomic particles that move around outside the nucleus. |
Orbital | area in an atom where electrons are likely to be found. |
Valence electron | An electron in the outermost energy level of an atom. |
Periodic law | States that when elements are arranged this way, similarities in their properties will occur in a regular pattern |
Period | Horizontal rows in the Periodic Table |
Group | Atoms of elements in the same group or column that have the same number of valence electrons and have similar properties. |
Ion | an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge. |
Atomic number | the number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element. |
Mass number | the sum of the numbers of protons and neutrons in the nucleus of an atom. |
Isotope | an atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons. |
Atomic mass unit (AMU) | a unit of mass that describes the mass of an atom or molecule; it is exactly one twelfth of the mass of a carbon atom with mass number 12. |
Average atomic mass | the weighted average of the masses of all naturally occurring isotopes of an element. |
Metal | an element that is shiny and that conducts heat and electricity well. |
Nonmetal | an element that conducts heat and electricity poorly and that does not form positive ions in an electrolytic solution. |
Semiconductor | an element or compound that conducts electric current better than an insulator but not as well as a conductor. |
Alkali- metal | one of the elements of Group 1 of the periodic table |
Alkaline- earth metal | one of the elements of Group 2 of the periodic table. |
Transition metal | one of the metals that can use the inner shell before using the outer shell to bond |
Halogen | one of the elements of group 17 of the periodic table (fluorine, chlorine, bromine, iodine, and astatine) halogens combine with most metals to form salt. |
Noble gas | an unreactive element of Group 18 of the periodic table (helium, neon, argon, krypton, xenon, or radon) that has eight electrons in iits outer level (except for helium, which has two electrons) |
Mole | the SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in 12 g of carbon-12 |
Avogadro's constant | equals 6.02 times 10 to the 23 power; the number of particles in 1 mol. |
Molar mass | the mass in grams of 2 mol of a substance. |
Conversion factor | a ratio that is derived from the equality of two different units and that can be used to convert from one unit to the other. |