(Multiple Choice, 30 pts)

Which is evidence that the reaction below is a redox reaction?
2Na + Cl2 → 2NaCl

A. The sodium atom is a pure element as a reactant and becomes part of a compound.
B. Two different elements take part in the reaction.
C. Oxidation occurs to both elements in the reaction.
D. There are no ions in the equation.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.