Test 1: Matter? Flashcards
What are the sub atomic particles (saps)?
Protons
Neutrons
Electrons
What forces repel each other?
Positives (+1 +1)
Negatives (-1 -1)
What forces attract teach other?
Opposites (+1 —-> -1)
What is the difference between an element and an atom?
An element can be diatomic.
What are the diatomic molecules?
Iodine Hydrogen Nitrogen Bromine Oxygen Chlorine Fluorine (With the little 2)
What is the difference between the atomic mass and the mass number?
Mass number: Full number
Atomic mass: Number with decimal
What does the atomic number represent?
The number of protons.
How do you find the number of neutrons?
Mass number - atomic number
Which sap determines the element?
Protons
What makes an atom stable?
Same number of protons and neutrons or slightly more neutrons than protons.
What makes an atom of neutral charge?
Same number of protons and electrons.
What makes a positive ion?
More protons than electrons.
What makes a negative ion?
More electrons than protons.
What are isotopes?
Atoms of the same element with varying number of neutrons.
What are radioactive isotopes?
Atoms where the number of neutrons greatly exceeds the number of protons.
What are some uses of radioactive isotopes?
- Carbon dating. Use C14 to date fossils (more carbon left: younger. Less carbon left: older).
- Use as radiation for medical treatments (kill cells).
What makes an atom CHEMICALLY stable?
When the element has a full outer shell. (Noble gases)
How do you make a chemically unstable element stable?
By giving, taking or sharing valence electrons.
What is the mass of each proton?
1 amu
What is the mass of each neutron?
1 amu
What is the mass of each electron?
0.0005 amu
What are trends in the periods of the periodic table?
- The number of valence electrons goes up one from left to right.
- Each period has the same number of shells.
What are trends in the groups of the periodic table?
- The number of shells goes up one from top to bottom.
- Each group has the same number of valence electrons.
What are valence electrons?
The number of electrons on the outer most shell.
Which group is unreactive?
Noble gases because they have full shells, they are complete.
Which groups are highly reactive?
Alkali metals and Halogens because they only need to gain or lose one electron to be complete.
What are some periodicities?
- Atomic radius
- Electronegativity
- Chemical Reactivity
- Ionization
What is the periodicity of atomic radius?
Going down it increases because a shell is added.
Going across it decreases because there are more protons and electrons (charges), more attraction, so everything gets pulled in and becomes closer (smaller).
What is electronegativity?
An atoms power of attraction to an electron in a chemical bond.
(Ability to attract electrons).
What is the periodicity of electronegativity?
Going down energy decreases because there are more layers of electrons in the way of the protons, so less attraction.
Going across energy increases because there are more protons and less electrons that need to be attracted (the element is getting more excited so more energy).
What is ionization?
The ability to get rid of and pull off electrons.
What is the periodicity of ionization?
Going down energy decreases because it takes less force to pull off an electron thats farther away from the attraction of the protons.
Going across energy increases because it takes more force to pull the electrons away, more protons holds the electrons with greater force.
What is chemical reactivity?
The ability of an element to react.
What is the periodicity of chemical reactivity?
Going across it starts high (alkali metals, very reactive, only need to lose one electron), decreases, increases (halogens, very reactive, only need to gain one electron).
What are characteristics of metals?
- Malleable
- Shiny (has lustre)
- Conducts electricity and heat
- Reacts with acid
- Melt at high temperatures
What are characteristics of non-metals?
- Brittle
- Dull
- Non-conductive
- Non-reactive
- Melt at low temperatures
What are characteristics of metalloids?
Has characteristics of both metals and non-metals.
What are 3 types of substances?
- Ionic compounds (metals bonded to non-metals)
- Molecules (non-metals bonded to non-metals)
- Metal objects (metals bonded to metals)