Fireworks and Metals/Non-Metals (Review Deck) Flashcards
What are the two pure substances?
Elements - Are substances that cannot be decomposed into a simpler substance (For example Helium, Copper, etc.)
Compounds - Are substances made up of two or more elements combined in fixed proportions
What are the two types of mixtures?
Heterogenous - When two or more elements/compounds are combined but not uniformly mixed (If the different ingredients can be seen like pizza, salad, cookies, it is considered heterogenous)
Homogenous - When two or more elements/compounds are combined, but are uniformly mixed (If the ingredients cannot be seen like cola, milk, and air it is homogenous)
How does each of the three states affect the molecule interaction?
Solid - Molecules are locked in place, and are not able to move past each other
Liquid - Molecules are not as densely packed, and are able to move past each other
Gas - Molecules are spread out, and move around very fast
Atoms are identical no matter the state?
True
What is matter
Everything that we touch and feel, and breathe, are matter, which are made of atoms
Can atoms have the ability to be broken down physically and chemically?
No atoms are not able to be broken down physically and chemically
What are the four components of an atom?
Nucleus - Is a extremely small and dense center of an atom, in which contains both the protons and neutrons
Protons - Are positively charged particles located in the nucleus
Neutrons - Are neutrally charged particles that are located in the nucleus
Electrons - Are negatively charged particles that surround the atom
What is the Atomic Number used for?
Scientists use it to show the amount of protons that are in the nucleus of the atom, and also shows the amount of electrons the atom has
What is the Mass Number used for?
The mass number is used to show the combined amount of both protons, and neutrons that are in the nucleus
What is the formula to find the amount of Neutrons
Mass number - Atomic number
What are Isotopes?
Are atoms of the same element, but have a different amount of neutrons and mass number
Why can’t electrons be pinpointed?
Electrons travel too fast for the human eye to see
What are Energy Levels
Every atom has energy levels that becomes increasingly further away from the nucleus each level, with the energy level closest to the nucleus having lowest energy
What are the Purposes of Energy Levels?
Electrons are able to fill out these energy levels
How Many Electrons can be Within Each Energy Level?
Energy Level 1: 2 x (1)^2 = 2
Energy Level 2: 2 x (2)^2 = 8
Energy Level 3: 2 x (3)^2 = 18
Energy Level 4: 2 x (4)^2 = 32
What is Excitation within Electrons
When Electrons are supplied with energy, they are able to jump from a lower energy level to a higher energy level (Called the transition from ground state to excited state)
What are the Three (maybe four) ways an Electron can Receive Energy
- An electrical current
- A flame
- A high energy light source
Another way is through a chemical reaction
What Happens After an Electron is Excited?
An electron is only excited momentarily, until it eventually falls back into ground state
What Happens When an Electron Goes Back to Ground State
There is a specific amount of energy (photon) that will be emitted which corresponds a specific colored light (called Fluorescence)
How Does Amount of Energy Affect Electrons
The more energy an electron is supplied, the farther distance it can jump in the energy levels
How does Amount of Energy Affect the Emitted Colors?
The color of light produce depends on how far the electron falls
Electron falling from 2 -> 1 produces low light energy
Electron falling from 5 -> 1 produces higher light energy
What are the 3 other Applications of Fluorescence?
- Counterfeit detection
- Glow in the dark mini putt
- Marine fish identification
What are the Three Steps on how Fluorescence Work in Glowsticks?
Electrons can also be provided energy by a chemical reaction called chemiluminescence or if exposed to high energy light (UV light)
Step 1: At the moment that the glowstick is cracked, the diphenyl oxalate will come into contact with the hydrogen peroxide, creating a peroxyacid ester
Step 2: When the peroxyacid ester decomposes, energy is released and excites the electrons within the dye compounds
Step 3: The electrons then return back to ground state, and releases the ‘glowing light’
How do Fireflies glow?
Fireflies contain D-Firefly Luciferin, which becomes excited and relaxed back to ground state by emitting cold light (hot light kills the firefly)
How do Certain Jellyfish Glow?
Jellyfishes contain luciferin, which can be oxidized within the presence of an enzyme called ‘luciferase’ which causes a chemical reaction that emits a photon of light
How is Chemiluminescence used for Blood?
It is a method used at a crime scene in which the iron found within hemoglobin can catalyze a reaction of luminol, which emits blue light for 30 seconds
What are the Eight Different Properties of Metals?
- Solid at room temperature (Mercury being the exception)
- Conducts heat and electricity
- Lustrous (Shiny)
- Malleable
- Ductile (Made into wire)
- Hard
- Dense
- Possesses high melting and boiling points
What are Valence Electrons?
Valence electrons are electrons located on the outermost shell which are able to be removed from the atom easily
What is the Valence Electron Trends?
Elements in the same row from left to right: Valence electrons will increase by one
Elements in the same column: Valence electrons stay the same
Remember that He only has 2 valence electrons
What is the Octet rule?
The octet rule states that the outermost shell must be full to achieve stability
What is Ionic Bonding?
An ionic bond is an electrostatic attraction between both an metal (cation), and an nonmetal (anion), which involves in an exchange of electrons
How do Cations and Anions Work Together?
Cations (metals) are positively charged atoms that are generated due to a loss in electrons
Anions (nonmetals) are a negatively charged atoms that are generated due to a gain in electrons
Both need each other in order to achieve a stable octet
How are Ionic compounds named?
Metal + nonmetal + ‘ide’
What are Metallic Crystals?
Has a shape that is similar to an ionic crystal, however all atoms are positive, which means there is no positive-negative reaction
How do Atoms in a Metallic Crystal Stay Together?
The Electron Sea Model shows the nuclei of metals are surrounded by a sea of delocalized electrons which are able to be distributed and moved across any atoms, which holds the entire crystal together
What is the Conductivity within the Electron Sea Model?
When energy is supplied to one end of the metal, the electrons from the current will hop through the electron sea and passes to the other end
An example of this is copper wires
What is the Shininess Within the Electron Sea Model?
Electrons are able to absorb any incoming light, and will re-emit the light which causes the metal to shine
What is the Malleability and Ductility of the Electron Sea Model?
The ionic crystal has delocalized electrons which helps keep the metallic lattice stable, as atoms move over each other, the electrons will move as well to keep the structure stable
Why are Ionic Crystals not Malleable?
If an ionic crystal were to be hit by a hammer, it would shatter because the atoms would slide past each other causing like charges to be next to each other, causing a strong repulsion, resulting in the crystal shattering
What is the Melting/Boiling Point in the Electron Sea Model
The attraction between the metal cations and the delocalized electrons are very high because they want to stay together, as delocalized electrons increases, the hardness, and boiling point also increases
What is Specific Heat Capacity?
A measurement of how much heat energy must be absorbed before it changes temperature
What are the Steps to Find the Specific Heat Capacity?
The Specific Heat Capacity can be found by using a technique called ‘calorimetry’
- A cube is first placed in a Styrofoam cup filled with a known amount of water at a known temperature
- Assuming the cup is insulated, whatever heat is gained/lost by the metal is then absorbed/withdrawn by the water
What are the Six Properties of Nonmetals
- Most are gaseous at room temp
- Are poor conductors for both heat and electricity
- Are dull and colorless
- Are brittle
- Low density
- Has a low melting point
What is the Reaction Between two Nonmetals Called?
The moment two nonmetals come into contact, the valence electrons are shared to create a stable octet calling a ‘covalent bond’
How are Covalent Compounds Named?
Same as ionic compounds except a prefix must be added for both nonmetals
prefix + nonmetal + nonmetal + ide
Prefixes would be:
1 = mono
2 = di
3 = tri
4 = tetra
5 = penta
6 = hexa
7 = hepta
8 = octa
9 = nona
10 = deca
What is Covalent Bonding?
Is when electrons are not shared equally, and instead is depended on the electronegativities of both atoms
What is Electronegativity?
The ability in which can atom can attract bonding electrons
What are all the Bond Types and Their Electronegativies?
Non-polar covalent: Equal sharing of electrons which has a electronegativity difference of < 0.4
Polar Covalent: Unequal sharing of electrons which has an electronegativity difference of between 0.4 and 1.8
Ionic Bonding: An ionic bond is formed due to the large electronegativity difference which is > 1.8
What is the Difference Between Covalent and Ionic Bonding?
Covalent bonding: Is when valence electrons are shared between atoms and exists as molecular units
Ionic Bonding: Is when valence electrons are transferred between each other and exists as a ordered array
What are the Five Properties of Metalloids?
- Are intermediates between metal and non-metals
- Most are solid at room temperature
- Some are able to conduct heat and electricity, like silicon and germanium
- Some are lustrous
- Tends to be brittle
Liquids are compressible and have a fixed volume| True or false?
False
Solids are incompressible and have a fixed volume
True or false?
True
Gases are compressible and have variable shape and volume| True or false?
True
