PERIODIC TABLE PLS HELP 20 POINTS

Ans 1.) Potassium ( 1 ) , palladium (2)

Metals are those which posses lustre, hardness, malleability, ductility etc.

Ans 2.) Oxygen ( 5 ) , Argon ( 4 )

Non metals are those elements which do not possess lustre, hardness, ductility, malleability etc... they are generally brittle in nature.

Ans 3.) Boron ( 3 )

Metalloids are those substances which shows both the properties of metals and nonmetals.

Ans 4.) Boron ( 3 )

Semiconductor are those substances whose conductivity is lie between insulators and conductors.

Ans 5.) Argon(4)

Least reactive gases are those gases which generally do not reactive with any element or having very least reactivity like argon which is noble gas.

Ans 6.) Oxygen (5)

Oxygen is dull, easily breakable and good insulator but only in solid form

Ans 7.) Palladium(2)

Malleability is the property of metals that is drawn metals into thin sheets .

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.