Atomic Structures Part 2

matter

a term used to describe substance that makes up all physical objects.

~ has shape, form and occupies volume

mass

a scientific term used to describe the density and type of atoms in any given object

~ unit is kilogram (kg) but can also be pounds (lb)

weight

the force acting on an object due to gravity

atom

the smallest particle that has all the properties of an element

mixture

~ one product of mechanical blending or mixing chemical substances such as segments and compounds, without actually chemical bonding or other chemical change so that each ingredient substance retains its own chemical properties and makeup

~ in chemistry, is a material made up of two or more different chemical substances which are not chemically bonded

~ physical properties such as melting point may differ from those of the components

~ can be separated into their components by using physical means

~ little or no energy change when a mixture occurs

~ still has each component with separate properties

~ think sand & water

chemical substance

~ may be well defined as “any material with a definite chemical composition”; can be either a pure chemical element or a pure chemical compound

~ a form of matter with a constant chemical composition and characteristic properties

~ often called “pure” to set them from mixtures

~ exists as solids, liquids, gases, or plasma and may change between these phases of matter with changes in temperature or pressure and time

~ may be combined or converted to others by mean of chemcial reactions

chemical element

~ a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species

~ cannot be broken down into simpler substances by any chemical reaction

~ number of protons in the nucleus is the defining property of an element, referred to as its atomic number

~ all atoms with the same atomic number are atoms of the same element

Z

the atomic number is represented by what letter?

molecule

atoms of various elements may combine to form ________.

ex: water

compound

any quantity of any one type of molecule

Ionic bond

a link from attraction between charged ions in a chemical compound. the valence electrons of one atom are transferred permanently to another atom

covalent bond

a chemical bond that involves the sharing of electrons to form electron pairs between atoms. a stable balance of attractive and repulsive forces between atoms, when they share electrons.

1913

what year did Neils Bohr improve his versions of the atom?

Niels Bohr

whose version of the atom is like a mini solar system where the electrons revolve around the nucleus in orbits or energy levels?

Greeks

what group of people thought all things are made of earth, water, air, and fire and that atoms were indivisible?

opposite

the electron and protons are equal but ________ charged.

1800

Mass of the electron is _______ times less than the proton or neutron

same

mass of the proton and neutron are almost ______

2n²

each shell can contain only a certain number of electrons and is equal to _____

n

what is the variable for the number of the energy shell used in finding number of electrons on a shell?

lead

_______ has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements

electrons

the group number on the top of the periodic table stands for the number of ________ on the valence shell of an atom

period

total number of electrons in an atom equals its ________ in the periodic table

valence

number of electrons in the outermost shell determines the ______ of an atom

Pb; 82

what is the symbol and atomic number of lead

lead

what element is found to be used in:

~ water applications such as weights for scuba divers and ballasts for sailboats

~ some bullets

~ glass on computers and TV screens to shield viewers from radiation

energy

ability to do work

mechanical energy

it is all the energy that an object has because of its motion and its position. all living things and all machines use __________ to do work.

potential energy

the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge and other factors

kinetic energy

energy of motion. the energy an object possesses due to its motion. it is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

having gained this energy during its acceleration, the body maintains this energy unless its speed changes. the same amount of work is done by the body when decelerating from its current speed to a state of rest

chemical energy

energy stored within chemicals, makes its energy inside atoms and molecules. the energy of chemical bonds, but the term also includes energy stored in the electron arrangement of atoms and ions

heat or thermal energy

energy obtained from the vibration of atoms and molecules of a substance due to its rise in temperature

electrical energy

energy an atom’s charged particles have to cause an action or move an object. the movement of electrons from one atom to another is what results in _________

nuclear energy

energy released during nuclear fission or fusion, used to generate electricity

electromagnetic energy

self-sustaining energy with electric and magnetic field components. AKA “light”, EM, EMR, or electromagnetic waves. the waves propagate through a vacuum at the speed of light. the oscillations of the electric and magnetic field components are perpendicular to each other and to the direction in which the wave is moving. waves may be characterized according to their wavelengths, frequencies, or energy

electron binding energy

the strength of attraction/attachment of the electron to the nucleus/orbit

stronger

the closer the electron is to the nucleus the ________ the electron binding energy

greater

the greater the total number of electrons in an atom, the _______ the binding energy of each electron

large

what size atom takes more energy to ionize? large or small?

increase

as you move up in the periodic table, the binding energy ________ because there are more protons in the nucleus

Wolfram

what is the other name for Tungsten?

74

what is the atomic number of Tungsten?

tungsten

What element has the highest melting point of metals and thus is used in x-ray tubes.