Unit 3, Periodic Table and Elements Flashcards
What is the center of an atom?
Nucleus
What is outside the nucleus?
energy layers
Where are electrons found in the atom?
The energy layers
What is a cation?
It is a positively charged atom
Where are protons and neutrons found in the atom?
The nucleus
What is an anion?
A negatively charged atom
What determines the identity of an element?
of protons
What determines the weight of an element?
Protons and neutrons
How much do protons and neutrons weigh?
1amu each
How many electrons fit on the 1st energy level?
2 electrons
What equation is for the # of electrons on each energy level?
2nsquared
How many electrons fit on the 2nd energy level?
8 electrons
How many electrons fit on the 3rd energy level?
18 electrons
What is the most stable # of valence electrons?
8 valence electrons
What did Mendeleev do?
He…
- arranged elements in increasing atomic mass
- stacked them by similar properties
- predicted properties of un-found elements
What are the 3 types of elements?
- Metals
- Non-metals
- Metalloids
What are properties of non-metals?
They…
- are bad conductors
- dull
- brittle
- gain electrons when reacting
What are properties of metals?
They…
- are good conductors
- shiny
- malleable
- ductile
- lose electrons when reacting
What are properties of Metalloids?
They are in between metals and non-metals
What are Alkali metals?
They…
- are all metals, except for hydrogen
- have 1 valence electron
- very reactive
- Want to lose 1 valence electron
What are Alkaline Earth metals?
They…
- metals
- have 2 valence electrons
- reactive, not as much as alkali metals
- want to lose 2 valence electrons
What is the Boron Family?
They…
- metalloids + metals
- named after Boron
- 3 valence electrons
- want to lose 3 valence electrons
What is the Carbon Family?
They…
- metals + non-metals + metalloids
- have 4 valence electrons
- many variations of bonds
- Want to lose or gain 4 valence electrons
- All organic molecules have carbon
What is the Oxygen family?
They…
- metals + non-metals + metalloids
- have 6 valence electrons
- Want to gain 2 valence electron
What is the Nitrogen Family?
They…
- metals + non-metals + metalloids
- have 5 valence electrons
- Want to gain 3 valence electrons
What are Halogens?
They…
- are all non-metals
- have 7 valence electrons
- most reactive non-metals
- Want to gain 1 valence electron
What are the Noble Gasses?
They…
- are all non-metals
- have 8 valence electrons
- don’t react, very stable
Why are high atomic # atoms unstable?
They are unstable because they need a lot of protons - needs more neutrons - weakens attractive force on electrons - exist for very little time
Why does the bottom left atoms of the periodic table have a bigger atomic radius?
This is because as we move to the rights of the periodic table there are more protons - more pull on electrons shrinking the atomic radius. Also, the bottom has more energy layers.
Why are the bottom left and top right of the periodic table the most reactive?
The bottom left is reactive because they are metals that lose electrons when reacting so a lot more energy layers result in a weaker attractive force from the nucleus which makes it much easier for the electrons to transfer to a different atom. The top right is more reactive aside from the noble gasses because they have fewer energy layers resulting in a more attractive force pulling on the valence electrons which combined with the fact that non-metals gain electrons when reacting, makes it much easier for them to pull electrons from metals.
