Chapter 3: The Structure of the Atom- Final Make Up

Which statements are part of Dalton's atomic theory?

1. In a chemical reaction, atoms are separated, combined, or rearranged. 2. Atoms of a specific element are different from those of another element. 3. Atoms are indivisible and indestructible.

The mass of an electron is ______.

9.1 x 10 ^-28 g

The smallest particle of an element that retains the properties of the element is called a(n) ____.

Blank 1: atom

True or false: Democritus's ideas were rejected, in part, because the experiments he performed refuted his claims.

False

One way in which Dalton's theory was not accurate was that it proposed that atoms ______.

are indivisible.

Which is radiation that originates from the cathode and travels to the anode of a cathode-ray tube?

cathode ray

What was Millikan able to determine through his oil-drop experiments?

charge and mass of an electron

When did scientists begin to be able to answer questions about the composition of the atom?

late 1800s

What were J.J. Thomson's cathode-ray tube experiments in the late 1890s designed to determine?

the charge-to-mass ratio of an electron

Dalton's atomic theory explains the law of conservation of mass because, according to the theory, ______.

the number of atoms of each type is the same before and after a reaction.

According to Dalton's atomic theory,

atoms are separated, combines, or rearranged in a chemical reaction.

Place these steps of Rutherford's gold foil experiment in order from first (top) to last (bottom).

1. A narrow beam of alpha particles was aimed at a thin sheet of gold foil. 2. A zinc-sulfide-coated screen produced a flash of light when struck by an alpha particle. 3. Researchers noted where the fashes occurred. 4. Researchers could then determine if the atoms in the gold foil deflected the alpha particles.

Which statements about the ideas of Democritus, Aristotle, and Dalton are true?

1. Aristotle believed that matter was made up of earth, air, fire, and water. 2. Both Dalton and Democritus proposed that matter is composed of extremely small particles. 3. Aristotle did not accept Democritus's ideas because he did not believe that empty space could exist.

Democritus's ideas were not accepted at the time he proposed them (or for thousands of years afterward) because

1. Aristotle, one of the most influential Greek philosophers, did not support them. 2. he was unable to back up his ideas with evidence from controlled experiments 3. science as we know it did not exist

Which of these aspects of Dalton's theory have turned out to be inaccurate?

1. Atoms are indivisible and indestructible. 2. Atoms of a given element are identical in size, amss and chemical properties.

Which describe J.J. Thomson's model of the atom?

1. It describes the atom as spherical. 2. It is sometimes called the "plum pudding model" 3. Its positive charge is uniformly distributed.

Several thousand years ago, people sought after the truth about the nature of matter by ______.

1. Thinking Intellectually 2. formulating explanations based on life experiences

Many early philosophers concluded that matter ______.

1. could be endlessly divided into smaller and smaller pieces 2. was composed of earth, water, air, and fire

A cathode-ray tube

1. depends on the use of a vacuum pump for its funtion 2. was used to study the relationship between mass and charge 3. has metal electrodes connected to opposite ends.

Democritus proposed that

1. the atoms that made up matter could not be created, destroyed, or further divided 2. matter was not infinitely divisible 3. He believed matter was made up of tiny particles called atomos

Rutherford conducted an experiment to see if ___________ particles would be deflected as they passed through _____ ______.

Bank 1: alpha Blank 2: gold Blank 3: foil

John Dalton's ideas about matter, which arose from his many experiments in which he studied the mass ratios of elements involved in chemical reactions, are collectively known as ______ _______ ________.

Blank 1: Dalton's Bank 2: atomic Blank 3: theory

It was not until nearly 1900 that scientists began to be able to answer questions about the composition of the ______.

Blank 1: atom

It was not until nearly 1900 that scientists began to be able to answer questions about the composition of the _____________.

Blank 1: atom

Radiation that originates from the cathode and travels to the anode of a cathode-ray tube is called a(n) _______ ________

Blank 1: cathode Blank 2: ray

J.J. Thomson's cathode-ray tube experiments in the late 1890s were designed to determine the ratio of an electron's _____ to its _______.

Blank 1: charge Blank 2: mass

Through his oil-drop experiments, Millikan was able to determine the _________ and ______ of an electron.

Blank 1: charge BLank 2: mass

Democritus proposed that matter was made up of atoms, which could not be ________, ________, or further divided.

Blank 1: created Blank 2: destroyed

Dalton's atomic theory supports the law of conservation of mass because in his theory, atoms are not created, _________, or divided in a chemical reaction. Therefore, the total _________ before and after the reaction does not change.

Blank 1: destroyed Blank 2: mass

A negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus is called a(n) ______.

Blank 1: electron

Thomson's cathode-ray tube experiments led him to identify the first subatomic particle, the ____.

Blank 1: electron

Aristotle did not believe that ________ ________could exist.

Blank 1: empty Blank 2: space

Many early philosophers concluded that matter was composed of four "elements": earth, air, ________ , and _______.

Blank 1: fire Blank 2: water

The mass of an electron is = 9.1 x 10^-28 g = the mass of a(n) _______ atom. 1/1840

Blank 1: hydrogen

Match the thinker or thinkers at left with their ideas at right.

Dalton > Different atoms combine in simple whole-number ratios to form compounds. Dalton and Democritus > Matter is made up of tiny particles that are indestructible and indivisible. Aristotle > Matter is made of earth, air, fire, and water.

What name is given to John Dalton's ideas about matter, which resulted from many careful measurements and observations?

Dalton's atomic theory

Which is the smallest particle of an element that retains the properties of the element?

atom

Several thousand years ago, science as we know it today ______.

did not exist.

Thomson's cathode ray-tube experiments led to the discovery of which subatomic particle?

electron

Which is a negatively charged, fast-moving particle with an extremely small mass that is found in all forms of matter and moves through the empty space surrounding an atom's nucleus?

electron

Aristotle believed that ______.

matter was made up of earth, fire, air, and water.