Electron
Which direction do GROUPS and PERIODS run on the periodic table?
Groups = Up and Down
Periods = Left to Right
Identify if each of the following are elements or not: (yes/no)
Ti NaCl Mg CO H Brass
Yes (Titanium) No (salt=compound) Yes (Magnesium) No (Carbon Monoxide=compound) Yes (Hydrogen) No (Brass=mixture)
Why is rust on iron, or tarnish spots on silver a chemical change?
There is a new substance formed that we cannot change back into the original substance
How many valence electrons do elements need to be "happy"? (Have a full outer shell, except Helium of course)
8
What TWO subatomic particles are located in the nucleus of the atom, weighting 1amu each?
Neutron and Proton
How do we find the number of valence electrons?
Look at the group number, or know that Transition Metals have 2-3
How are compounds combined? (Chemically or physically)
CHEMICALLY
Is this a physical or chemical change? EXPLAIN
Two chemicals combine and create a gas
Chemical = a new substance is produced
What 3 elements make up sugar/glucose?
Compound Formula fill in the blank shown below
__6 ___12 ___6
Carbon (C)
Hydrogen (H)
Oxygen (O)
What are the charges of the 3 subatomic particles within an atom? Electron, Proton, and Neutron
Negative, Positive, and Neutral
Does reactivity increase or decrease when going DOWN a GROUP?
INCREASE
What is a substance that is NOT chemically combined, and can be separated by physical means?
a MIXTURE
Is this a physical or chemical change? EXPLAIN
Salt is dissolved in water
Physical = no new substance is produced and you can get the salt back out of the water through evaporation
Where are ALL OF the NON METALS located on the periodic table? (can point, name them, etc, must include each one)
Hydrogen = top left of the table in group 1
The Rest= to the right and above the metalloids (top right of the table)
How do atoms bond into a molecule? (what subatomic particle is used)
VALENCE electrons
Which group is MOST reactive with group 1 (name both of these families)
The HALOGENS (group 17) is most reactive with the ALKALI METALS (group 1)
Is this a heterogenous or homogenous mixture?
Saltwater
HOMOGENOUS
Name 3 PHYSICAL properties
Boiling Point Conductivity
What law is described here:
"matter cannot be created or destroyed"
The Law of Conservation of Matter/Mass
Find the number of Neutrons in an atom of Scandium (Sc) using the periodic table
atomic mass is 44.9 = rounded to 45
atomic number is 21
so 45 - 21 = 24
What family of elements is located on the staircase, and act a bit like metals, and a bit like nonmetals
METALLOIDS
Is this a heterogenous or homogenous mixture?
Bronze
HOMOGENOUS
flammability
toxicity
reactivity
combustibility
Balance this equation! (you can use the board)
C + S8 → CS2
4 C + S8 → 4 CS2