Question

ing parts of an atom
ideas about matter

1. many ancient greek philosophers thought that all matter was made of only four

elements—fire, water, air, and _______________.

1. these early scientists were not able to _______________ their theories.
2. democritus proposed that matter is made of small, indivisible objects

called _______________.

1. he proposed that different types of _______________ are made from

different types of atoms.
b. dalton’s atomic model

1. john dalton proposed the _______________ theory, which was based

on careful observations and _______________ of chemical reactions.

1. dalton’s theory states that atoms cannot be divided, _______________,

or destroyed.

1. it also stated that atoms of one _______________ are different from

atoms of other _______________.
the atom

1. a(n) _______________ is the smallest piece of an element that still

represents that element.
atoms were first seen by using a(n) _______________ microscope.
mson—discovering electrons
thomson discovered that the rays in a(n) _______________ were
tracted to a(n) _______________ charged plate, which means that the
s have a(n) _______________ charge.
mson’s atomic model stated that an atom is a positively charged
_____________ with _____________ throughout it.
d—discovering the nucleus
ford’s student performed an experiment during which they shot
_____________ particles into a piece of _____________

Explanation:

Part A: Ideas About Matter

1. Explanation for Q1: Ancient Greek philosophers' four-element theory included earth as the fourth element (along with fire, water, air).

Answer:

earth

1. Explanation for Q2: Early scientists lacked methods to test/verify their theories (experimental validation was limited).