Show:
true / false
physical/chemical changes
periodic table
chem. terms
100
You can't see the different parts of a homogeneous mixture.
True
100
The crushing of a can is an example of (physical or chemical?)
physical
100
H  stands for what on the periodic table?
Hydrogen
100
what is an atom?
smallest unit of matter
200
Solids have a high energy level.
False
200
burning a  hole in a newspaper is an example of a physical or chemical change?
chemical
200
what is the atomic number of Nitrogen?
7
200
define atomic number.

the number of protons in the nucleus of an atom of an element.

.
300
In exothermic heat gives in in endothermic heat exits.
False
300
Give an example of a physical and chemical change.(both having to do with wood)

physical- cutting a piece of wood in half with an axe.

chemical- burning the wood or setting it on fire.

Answer may vary.

300
How many neutrons does sodium have if it's atomic number is 11 and the mass 23.
12
300
Define atomic mass

The average mass of atoms of an element.

400
 a helium atom is  a type of nuclear decay in which a nucleus  emits an alpha  particle.
true
400
sublimation of dry ice.. physical or chemical?
physical
400
what element contains 49 protons and electrons?
in (indium)
400
Describe the role of the quantum mechanical model
Electrons in clouds or orbitals  act like particles and waves.
500

1)The molar mass of Cr4(P2O7)3 is 729.8 g/mol

2) The molar mass  of CaCOH.  is 95.6 g/mol

1) true 

2)false  correct answer is 69.09 g/mol

500
what happens when salt dissolves into water. physical or chemical ? Please explain in detail
when you dissolve salt into water the salt dissociates into ions from NaCl into Na+ and Cl-
500
how many valence electrons does Br have? how many protons and neutrons does Br have?

7  

35 

45

500
Explain how you could tell if a solution's unsaturated, saturated, and supersaturated on a graph.

unsaturated- found under the line

saturated -is found on the line

supersaturated- is found above the line