Atomic Structure
What is the atomic number for chromium (Cr)?
24
What type of matter is chlorine (Cl) gas?
physical
What is the formula for density?
D=mass/volume
What type of elements make ionic compounds?
Metal and nonmetal
What does atomic number tell you?
The number of protons.
heterogeneous mixture
chemical
What are the two sets of units for density?
g/ml or g/cm3
Metals always are _____ charges and nonmetals are always ______ charges.
metals = positive
nonmetals = negative
How many neutrons does cobalt (Co) have?
32
Homogeneous - uniform, looks like 1 thing
Heterogeneous - not uniform, can see multiple components and pieces
What type of change is dissolving sugar in coffee?
physical
1.189 g/ml
What is the name of RaCl2?
radium chloride
neutrons = atomic mass - protons
What is the difference between element and compound?
element - 1 type of atom
compound - many types of atoms
Describe two physical changes that can happen to a rod of iron.
answers may vary (melt, cut, bend, paint)
A piece of copper has a density of 8.92 g/cm3 and a volume of 8.00 cm3. What is the mass in grams of the piece of copper?
**HINT: rearrange formula**
71.4 grams
What is the name of FrI?
Francium iodide
What makes atomic mass?
protons & neutrons
The air that we breathe is a blend of oxygen gas, nitrogen gas, and carbon dioxide gas. How would you categorize air?
homogeneous mixture
Describe a chemical change that can happen to iron.
answers may vary (rust, oxidize, acid)
What is the density of a solid piece of iron that has a mass of 11.78 g and is 3.0 cm long, 1.0 cm wide, and 0.50 cm thick?
v= l*w*h
7.85 g/cm3
What is the formula for calcium phosphide?
Ca3P2