Chapter 4 - The Atom Flashcards
Who was one of the first people to introduce atomic theory?
Powerpoint
Leucippus (and his student Democritus)
400BC
What was the original name for the atom and what did it mean?
Powerpoint
atomos - indivisible
Who was John Dalton, what did he do, and when?
Powerpoint
- English chemist
- developed atomic theory based on evidence
- theorized molecules and compounds
- atomic model was a sphere
- 1800s
Who was Dmitri Mendeleev, what did he do, and when?
Powerpoint
- developed periodic table of elements
- theorized atomic similarity based on weight
- 1869
Who was Joseph John Thomson, and what did he do?
Powerpoint
- discovered the existence of electrons
- atomic model was positive spherical mass with negatively charged electrons suspended inside
Who was Ernest Rutherford, and what did he do?
Powerpoint
- gold foil experiment
- discovered there was space between the positive nucleus and the electrons and created a new atomic model to reflect this
Who was Niels Bohr, and what did he do?
Powerpoint
- concluded each atom’s properties are unique
- came up with atomic model that has electrons in a series of orbits
What is an atom called when it loses an electron and becomes positively charged?
Powerpoint
CATION / POSITIVE ION
What is an atom called when it gains an electron and becomes negatively charged?
Powerpoint
ANION / NEGATIVE ION
What is the nuclear force that holds atoms together called?
Powerpoint
BINDING ENERGY
What is the formula used to determine the maximum number of electrons that can go in a shell?
2n^2
n = electron shell number
What is the octet rule?
Powerpoint
rule in electron configuration that the valence (outermost) shell of an atom can never have more than 8 electrons in it
What does the atomic number tells us about an atom?
Powerpoint
how many protons it contains
Z number (subscript)
What does the atomic mass number tells us about an atom?
Powerpoint
how many protons AND neutrons it contains
A number (superscript)
What is an ISOTOPE?
Powerpoint
atom with the same number of protons, but a different number of neutrons
What are the rows of the periodic table called?
Powerpoint
PERIODS
What are the columns of the periodic table called?
Powerpoint
GROUPS
What is the type of bond in which one atom gives an electron to another atom?
Powerpoint
IONIC BOND
What is the type of bond in which two atoms share an electron?
Powerpoint
COVALENT BOND
What is an atom called when it gains an electron and becomes negatively charged?
Book
ANION / NEGATIVE ION
What is an atom called when it gains an electron and becomes negatively charged?
Powerpoint
ANION / NEGATIVE ION
In the periodic chart of elements, the group numbers are based on:
Review
HOW MANY ELECTRONS ARE IN THE VALENCE SHELL
What is defined as the volume of space within an atom in which a pair of electrons must reside?
Review
ORBITAL
Compared to an electron, how much more massive is a neutron?
Review
A NEUTRON IS MORE MASSIVE THAN AN ELECTRON BY THE MASS OF ONE PROTON
Which type of chemical bonding between atoms occurs because of a “defect” in the distribution of negative charge that forms a smooth screen around the atom?
Review
COVALENT BOND
Why is an ionized atom able to affect other atoms from a substantial distance?
Review
IT HAS A CHARGE AND THIS CHARGE WILL ATTRACT AN OPPOSITE CHARGE DUE TO ELECTRICAL FORCES
In the anode disc of an x-ray tube, what “knocks” electrons out of their normal shells in the tungsten atoms?
Review
HIGH SPEED ELECTRONS FROM THE CATHODE FILAMENT
What is defined as an atom which is unstable due to an N number well outside the normal range?
Review
RADIOISOTOPE
What is defined as the “splitting” of an atomic nucleus?
Review
NUCLEAR FISSION
When a beta particle is emitted from a radioactive atom, what happens to its atomic number?
Review
ITS ATOMIC NUMBER INCREASES BY 1 BECAUSE A NEUTRON DECAYS TO LEAVE A PROTON AND EMIT AN ELECTRON
When gamma radiation is emitted from a radioactive atom, what happens to its A number?
Review
IT DOES NOT CHANGE - ONLY WAVE ENERGY IS LOST, NOTHING IS TRANSMUTED
As a result of an alpha particle being emitted from an atom, which way and how far does the atom move on the periodic chart?
Review
THE ATOM MOVES TWO PLACES TO THE LEFT BECAUSE IT IS LOSING TWO PROTONS - PROTONS MAKE UP THE Z NUMBER
The lowest energy level possible for a particular atomic nucleus is called its:
Review
GROUND STATE
What is defined as the forcing together of two smaller nuclei to form a single, larger nucleus?
Book
NUCLEAR FUSION
What is a radionuclide?
Book
any atom which is radioactive
What does it mean to be radioactive?
Book
a radioactive atom has an unstable nucleus due to having too many or too few of neutrons
What describes the changing of one element to another by radioactive decay?
Book
TRANSMUTATION
What is an isomer?
Book
an element that has emitted an alpha particle and has some energy left in the nucleus as a result - it will emit a gamma ray to get rid of this excess energy and become more stable
