Atomic Structure

Which sentences about atoms, matter, and electric charge are true?

The positively charged subatomic particle that remains when a hydrogen atom loses an
electron is called ...

What isotope of carbon has been chosen as the reference isotope for atomic mass
units? What is the defined atomic mass in amu of this isotope?

What are the horizontal rows in the periodic table called?

How many neutrons does a beryllium atom with four protons and a mass number of
nine have?

List two reasons why the ideas of Democritus were not useful in a scientific sense.

Welche ist richtig ?

Which statements about Dalton’s atomic theory are true?

About how many atoms of copper when placed side by side would form a line 2.8 cm
long?

What charge does a neutron carry?

»Isotopes are chemically alike because they have identical numbers of protons and
electrons.«

In the periodic table, the elements are organized into groups based on ...

The total number of protons and neutrons in an atom is its ...

Thomson observed that the production of cathode-rays did not depend on the kind of
gas in the tube or the type of metal used for the electrodes. What conclusion did he
draw from these observations?

Explain why in 1911 Rutherford and his co-workers were surprised when they shot a
narrow beam of alpha particles through a thin sheet of gold foil.

Match the following terms from the experiments of Thomson with the correct
description.

1.) an electrode with a negative charge

2.) a glowing beam travelling between charged electrodes

3.) an electrode with a positive charge

4.) a negatively charged particle

Democritus, who lived in Greece during the fourth century B.C., suggested that matter
is made up of tiny particles that cannot be divided. He called these particles ...

Which statements are true about the nuclear theory of atoms suggested by
Rutherford’s experimental results.

How do atoms of neon-20 and neon-22 differ?

How many protons, neutrons, and electrons has one atom of the element 22/10 Ne ?

1.) protons

2.) neutrons

3.) elctrons

What is the mass number of a helium atom that has two protons and two neutrons?

Why is the atomic mass unit (amu), rather than the gram, usually used to express
atomic mass?

Designate the element 22/10 Ne in the form »name of element« – »mass number«.

When chlorine occurs in nature, there are three atoms of chlorine-35 for every one
atom of chlorine-37. Which atomic mass number is closer to the average atomic mass
of chlorine?

Neon-20 and neon-22 are called ...

»The atomic mass of an element is always a whole number of atomic mass units.«

Elements are different because their atoms contain different numbers of ...

Match the designation of each hydrogen isotope with its commonly used name.

1.) hydrogen-1

2.) hydrogen-2

3.) hydrogen-3

A hydrogen atom loses an electron. Which is the relative electrical charge remaining?

Which subatomic particles carry a negative charge?

How is the atomic theory that is accepted today different from Dalton’s atomic theory?

The modern process of discovery about atoms began with the theories of an English
schoolteacher named ...

Which statements about the average atomic mass of an element and the relative
abundance of its isotopes are true?

Suppose you could grind a sample of the element copper into smaller and smaller
particles. The smallest particle that could no longer be divided is ...