The Atom: From Philosophical Idea to Scientific Theory

The Atom: From Philosophical Idea to Scientific Theory

Multiple Choice

Which of the following statements of Dalton’s atomic theory describes conservation of mass?

• All matter is composed of atoms.

• Atoms of a given element are identical in size, mass, and other

• Atoms cannot be subdivided, created, or destroyed.

• Atoms of different chemical elements combine in simple whole number ratios to form chemical compounds.

Multiple Choice

The fact that every sample of a particular chemical compound contains the same elements in exactly the same proportions by mass is known as the law of...

• definite proportions

• multiple proportions

Fill in the Blanks

In an experiment, Alex and Rachel discover that their sample of table salt, also known as sodium chloride, NaCl, consists of 39.34% by mass sodium, Na, and 60.66% by mass chlorine, Cl. Later, Alex wonders what the percentage of Na might be in the table salt in his saltshaker at home. Rachel tells him, correctly, that it is...

Multiple Choice

If two or more compounds are composed of the same two elements, then the ratio of the masses of the second element that is combined with a certain mass of the first element is always a ratio of small whole numbers. This statement is called the law of...

• definite proportions

• conservation of mass

• atomic theory

• multiple proportions

Multiple Choice

Which is one way that Dalton’s atomic theory has been shown to be incorrect?

• Atoms can change identity in chemical reactions.

• Atoms can be split into subatomic particles.

• Atoms can be destroyed by chemical reactions.

• Some atoms of a particular element are identical to atoms of other elements.