Science: Unit 1, Chapter 3, Elements and The Periodic Table
energy level
a region of an atom in which electrons of the same energy are likely to be found
periodic table
an arrangement of elements in which the elements are separated into groups based on a set of repeating properties
the __________________ tells the number of protons in the nucleus of every atom in an element.
atomic number
A ____________ is the particle of an atom that moves rapidly in the cloudlike region around the nucleus.
electron
The sum of the protons and neutrons in the nucleus of an atom is the __________________.
mass number
The positively charged particle if an atom is called a __________.
proton
Which two particles in an atom are equal in number?
protons and electrons
What two particles account for almost all the mass of an atom?
protons and neutrons
Which two particles are found in an atom's nucleus?
protons and neutrons
What three particles are found in an atom?
protons, neutrons, electrons
What do elements in the same group have in common?
same number of valence electrons and similar chemical properties
atomic number
the number of protons in the nucleus of an atom
luster
the quality of giving off light, brightness, glitter, brilliance
Isotope
Atoms of the same element that have different numbers of neutrons
How are elements identified in terms of their atoms?
By their atomic number
Mendeleev
Created the first periodic table. Arranged elements by increasing atomic mass
True or False? Moving across the periodic table from left to right, one finds, in order, metals, gases, then nonmetals
False. Metalloids not gases.
What do elements in the same period have in common?
In the same family, similar characteristics.
proton
Small, positively charged particles that are found in the nucleus of an atom
atomic mass
The average mass of all the isotopes of an element
Atom
The basic particle from which all elements are made; the smallest particle of an element that has the properties of that element.
nucleus
The central core of an atom containing protons and neutrons
Electron
A tiny, negatively charged particle that moves around the nucleus of an atom.
metal
A class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity.
group
A column on the periodic table of elements
period
A horizontal row of elements in the periodic table
neutron
A small particle in the nucleus of the atom, with no electrical charge
An element's ____ is its column in the periodic table.
group
atoms of the same element that have different numbers of neutrons are called _____________.
isotopes
What physical properties are shared by most metals?
luster, malleability, ductility, conductivity, solid at room temp.
A particle with no charge is a _____________.
neutron
The ____________ is the very small, dense center of an atom.
nucleus
chemical symbol
one or two letters that represent an element
An element's ____ is its row in the periodic table.
period
