UNIT 4 STRUCTURE OF ATOM & PERIODICTY

Question 1

bohr model

Answer 1

Neils Bohr proposed a model of an atom where the nucleus is the center containing protons and neutrons, and electrons orbit the nucleus in distinct energy levels in spheres- depicting a miniature solar system

Question 2

atom

Answer 2

smallest unit of an element; consists of a nucleus containing positively charged protons, neutral neutrons, and surrounded by negatively charged electrons orbiting in shells

Question 3

electrons

Answer 3

negatively charged subatomic particles that orbit the nucleus of an atom

Question 4

quantum mechanical model

Answer 4

a model of the atom that describes the probability of finding electrons within given orbitals by a three-dimensional model; the probability of finding an electron is calculated by the Schrodinger equation

Question 5

orbital

Answer 5

the space around an atom’s nucleus where specific pairs of electrons can be found; is characterized by specific shapes and energy levels (s,p,d, or f)

Question 6

electrons energy level

Answer 6

distinct distances from the nucleus of an atom where electrons may be found; will exist in a ground state energy level, n=0, until it is excited or given energy - then it can move to different energy levels

Question 7

electrons sublevel

Answer 7

energy levels around the nucleus of an atom that is divided into sublevels or subshell; sublevels within a shell

Question 8

electrons orbital

Answer 8

three dimensional region around an atom’s nucleus where an electron is most likely to be found

Question 9

electron shell

Answer 9

specific energy levels surrounding an atom’s nucleus; the outside part of an atom around the atomic nucleus

Question 10

principal quantum number

Answer 10

(denoted by n), represents the size of an electron orbital and its energy level within an atom

Question 11

Coulomb’s law

Answer 11

the force of attraction or repulsion between two charged bodies is directly proportional to the product of their charges and inversely proportional to the square of the distance between them; like charges repel, opposite charges attract

Question 12

electrons electric force

Answer 12

the electrostatic attraction or repulsion between negatively charged electrons

Question 13

equation for Coulomb’s law

Answer 13

F = k * (q1 * q2) / r²

Question 14

valence electrons

Answer 14

the electrons int he outermost shell, or energy level, of an atom

Question 15

core electrons

Answer 15

the inner electrons of an atom that are not considered valence electrons and do not participate in chemical bonding

Question 16

atomic radius

Answer 16

the distance from the atom’s nucleus to the outer edge of the electron cloud

Question 17

shielding effect

Answer 17

the phenomenon where inner electrons in an atom block the positive charge of the nucleus from reaching the outer electrons

Question 18

inner & outer electrons

Answer 18

inner electrons: located in the lowest energy levels closest to the nucleus of an atom
outer electrons: the electrons located in the outermost energy level of an atom

Question 19

ions

Answer 19

an atom or group of atoms that has an electric charge; ions with positive charge are called cations, ions with negative charge are called anions

Question 20

ionization energy

Answer 20

the amount of energy needed to remove the valence electrons of an atom

Question 21

Heisenberg uncertainty principle

Answer 21

states that its impossible to know both the exact position and momentum of a particle simultaneously with perfect accuracy

Question 22

Schrodinger equation

Answer 22

an equation in quantum mechanics that describes the wave function of an election

Question 23

quantum numbers

Question 24

principal quantum number

Question 25

angular momentum number

Question 26

electron spin quantum number

Question 27

s orbital

Question 28

p orbital

Question 29

electron configuration

Question 30

Aufbau principle

Question 31

Hund’s rule

Question 32

Pauli exclusion principle

Question 33

atomic radii

Question 34

ionic radius

Question 35

electron affinity

Question 36

electronegativity

Question 37

atomic theory

Question 38

early atomic theory

Question 39

ground state