Worksheet: Development of Atomic Theory Name _ True-False: put a T for True and F for False to the right of each statement

Dalton's atomic theory stated:

atoms are indivisible.

all atoms of the same element are alike.

atoms unite in small, whole number ratios

to form compounds.

The Greek philosopher Democritus was one of the first to suggest the existence of atoms.

The word "atom" means invisible.

A theory is an explanation of observable facts and phenomena.

Aristotle supported the idea of the atom.

From the "gold-foil" experiment it was concluded that the atom is mostly empty space.

Short Answer and Fill in the Blanks:

What must models and theories do in order to remain valid?

a.

b.

The "gold-foil" experiment had the following results: of the alpha particles were deflected, of the alpha particles were reflected, and of the alpha particles passed through the gold foil.

what are the statements

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph