Structure of the atom Flashcards
Define the periodic table
Grade that arranges all elements
How many elements are there?
118
How are the elements group?
Grouped in similar groups or categories
How are the elements arranged?
In order of increasing atomic number
Define atomic number
Number of protons in the nucleus of one atom of an element
What information does the periodic table give us?
Items and their sub atomic particles. Each element has a symbol, atomic mass and number
What is atomic mass represented by?
A
Define atomic mass
Total number of nucleons in the nucleus
What is the formula to calculate the number of neutrons?
Number of neutrons = A - Z
What is atomic number is represented by?
Z
When do you round off the atom number if it is not whole in the neutrons?
After your calculations
What are groups in the periodic table?
Eighteen groups – vertical
What are periods?
Seven period – horizontal
Why are elements in the same group?
Similar chemical properties
Define strength or brittleness
How easily a substance breaks
Define malleable
Ability of a substance to re-shape without breaking
Define ductile
Ability of substance to be drawn into thin strands
Define melting and boiling points
Temperature at which a solid changes to a liquid
Define electrical conductivity
Ability of a substance you allowed charge to flow through it
Define heat conductivity
Ability of a substance to transfer heat
Define metallic lustre
How shiny (metal) or non-shiny (non-metal) a substance is
Define phase at room temperature
Solid, liquid or gas
What chemical properties do metals have?
- Strong, malleable and ductile
- High melting or boiling points
- Good conductors of heat and electricity
- Mainly solid at room temperature except mercury as it is a liquid
- Metallic lustre
What chemical properties do nonmetals have?
- Brittle
- Low melting or boiling points
- Poor conductors of electricity and heat
- Solid liquid and gas at room temperature
- Doll looking
How do electrons move?
They move in a defined concentric circles or an energy levels
What part of the atom are closest to the nucleus?
Electrons
How many electrons should be placed in the first energy level?
Two electrons
How many electrons move in the first energy level?
The S orbitals
Which energy level has the lowest amount of energy?
The first energy level
Which energy levels have a higher energy?
Electrons in higher levels further away from the nucleus have higher energy
Why is the arrangement of electrons not simple?
Each energy level they are electrons that move on orbitals
Define orbital
Most probable region in which an electron may be found
How many electrons are in the second energy level?
Eight electrons
How do the electrons move in the second energy level?
S (2 e-)
P (6e-)
How many S orbitals and P orbitals are there in the second energy level?
1S orbital
3P orbitals
How many S orbitals and P orbitals are there in the third energy level?
1S orbital
3P orbitals
Which directions to the S and P orbitals go in?
S and P orbitals go in different directions
What determines how an element reacts?
Electrons in the outermost energy level that determine how an element reacts
What is the Aufbau diagram?
Represents the arrangement of electrons
How are the orbital is represented in the Aufbau diagram?
By a block
How are the electrons is represented in the Aufbau diagram?
Arrows
What are the three rules of the Aufbau diagram?
Aufbau principle, Hund’s rule, and Pauli’s exclusion principle
Define the Aufbau principal
An electron her first enter an orbital which is the lowest possible energy
Define Hund’s rule
No pairing of electrons. PX, PY, PZ orbitals before each orbital contains one unpaired electron
What is Pauli’s exclusion principle?
Orbital contains two electrons which must be the opposite spin
What are valence electrons?
The electrons in the outer most energy level of valence electrons. Valence electrons come into contact with
other atoms. This is chemical reactions
What is the Lewis diagram?
Indicate number of valence electrons and the arrangement
How is the Lewis diagram constructed?
Dots and crosses are drawn around the symbol. Top, bottom, top
What numbers are used to determine the Lewis diagram?
1 2 3 4 5 6 7 8
What substances give electrons?
Mostly metals. Cations (positive)
What substances receive electrons?
Mostly non-metals. Anions (negative)
What do you full up first on the Lewis diagram?
The s orbital - 2 dots
How do we full up the p orbital in the Lewis diagram?
Order to full. Top, bottom, top
What is the goal for an electron in the Lewis diagram?
To have 8 (noble gas)
How does an electron gain eight valency?
Bond get 8 spaces. Receive/give electrons
What is the highest number of electrons in an orbital?
Valency
When the valency numbers are + or - what does this mean?
Ions
What is an ion and what is it used for?
Naming formulas, swap and drop
Ions are charged atoms
What do atoms of most elements have?
Bond that each atom has 8 valence electrons in the outermost energy level
How do atoms get 8 valence electrons in the outermost energy level?
Atoms may lose, gain or share electrons with another atom
Generally most atoms don’t have 8 electrons. What do they have?
Few electrons. Some atoms lack one or two
Atoms that have fewer electrons means what?
Atoms may lose valence electrons easily. Until what remains a lower energy level which contains 8
What is valency?
Number bonds an atom of a particular element can make when bonding with another atom.
Is valency see the same as valence electrons?
Not the same as the number of valence electrons but it depends on them
Define valency
Number of electrons in an atom is able to lose, gain or share. Use groups to determine
What is the order of valence electrons?
1 2 3 4 3 2 1 0
What does a metal and a non-metal equal to?
Ionic bond
What happens when the metal atom transfers electrons to the non-metal?
Metal atom becomes positively charged which is a cation. Non-metal atom becomes negatively charged which is an anion
What is the formation of ions?
Atom loses or gains electrons. The number of electrons are no longer equal to protons. Therefore it is no longer electrically neutral as the charge changed
Define ion
Atom that has become charged by gaining or losing electrons
What do we use to determine the ionic charge(magnitude)?
Valency
What do we use to determine if it is a metal or non-metal(cation/anion)
+1+2+3+-4-3-2-1
What is all matter made up of?
All matter is made up of tiny or ticked called atoms
What is an atom?
An atom is the smallest part of an element that can exist on its own. Atoms in an element cannot be broken down into anything simpler by physical or chemical means
What is the charge of a proton? Where is it found?
Positive charge found in the nucleus
What is the charge of a neutron? Where is it found?
Have a neutral charge found in the nucleus
What is the charge of a electron? Where is it found?
A negative charge found orbiting the nucleus
Why are atoms always neutral?
The number of protons equal the number of electrons. Means that the number of positive charges is equal to the number of negative charges
What is an ion?
Adding or removing electrons will result the atom to be charged. A chafed atom is an ion. The atom is no longer neutral but stable. It does not changed the identity of an atom.
How does an ion become negatively charged?
If it gains electrons
What are negative ions called?
Anions
How does an ion become positively charged?
it loses electrons
What are positive ions called?
Cations
What usually forms cations?
Metal atoms and elements
What are isotopes?
Isotopes are atoms with the same number of protons but different number of neutrons. Therefore different mass.
What gives an atom it’s identity?
Protons
What is an element?
An element is a pure substance made up of one type of atom and that cannot be broken down into simpler substances
What does the atomic number tell us?
Tells us the number of protons and electrons present in the nucleus of an atom. there are a number of them
What does the atomic mass tell us?
Tells us the total number of nucleons in the nucleus
What is group 1 called?
Alkali metals
What is group 2 called?
Alkali earth metals
What is group 17 called?
Halogens
What is group 18 called?
Noble gases or inert gases
How are elements classified?
Elements are classified as metals, non-metals, and semi-metals (metalloids)
What does metalloids form on the periodic table?
The metalloids form a staircase which divided the periodic table
Where are metals found?
Metals are found on the left of the staircase. Hydrogen is an exception
Where are non-metals found on the periodic table?
On the left side of the staircase
What is a diatomic element?
Elements which naturally occur as molecules made up of two identical atoms chemically bonded. They must be identical
Name the diatomic elements
Hydrogen Nitrogen Fluorine Oxygen Iodine Chlorine Bromine
have no fear of ice cold bear
What is a pure substance?
Cannot be separated by chemical means. Split into two groups. Elements and compounds
What is an element?
A pure substance made up of tiny particles called atoms. Pure because it is made up of one type of atom only
What is a compound?
Consists of two or more different elects chemicals bonded together in a fixed portion
What is an impure substance/mixture?
The result of a combination of two or more substances not reacted chemically. Can be separated by physical processes
Why is it called impure substance?
Their portion may vary
What is a heterogenous mixture?
The component parts can be distinguished
What is a homogenous mixture?
Component parts cannot be distinguished
What is diffusion?
The movement of particles from an area of high concentration to one of low concentration, until the particles are evenly distributed compounds
What is a binary compound?
A binary compound if one in which there are atoms from two different elects present
What does the position of electrons mean?
Due to the position of electrons the electrons can either leave or enter an atom. Hence, changing the charge of a neutral atom
What happens when an atom loses electrons in static electricity?
When an atom loses electrons it gains a positive charge. They are more protons and electrons are present. There is a deficient of electrons
What does it mean when atoms gain electrons in static electricity?
When atoms gain electrons there have a negative charge. More electrons and protons are present as there is an excess of electrons
How do electrons transfer in electrostatic discharge?
Electrons are transferred from one object to another Wayne Road closed without touching
What is an ionic solution?
And ionic solution is one in which an ionic solid (which consists of a metal bonded to a non-metal) is dissolved in a solvent, usually water
