4.1,4.1,4.3 test

If 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of element Y would combine with 14 grams of X to form the same compound?

28 grams

What provides the best analogy for an electron in an atomic orbital?

A bee trying to escape from a closed jar.

Which statement about subatomic particles is true?

An electron has far less mass than either a proton or neutron

The _____________ of an isotope is the sum of the number of protons and neutrons in its nucleus (two words)

Atomic Mass

To find the number of neurons in an atom, you would subtract...

Atomic number from mass number

What is not part of John daltons atomic theory?

Atoms contain subatomic particles

The moving blades of an airplane propeller provide an analogy for the electron ____ model.

Cloud

In Bohr's model of the atom, _________ move in fixed orbits around the nucleus

Electrons

What statement accurately represents the arrangement of elections in Bohr's atomic model?

Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.

Who provided evidence for the existence of a nucleus in an atom?

Ernest Rutherford

How was Bohr's atomic model similar to Rutherford's model?

It described a nucleus surrounded by a large volume of space

In Niels Bohr's model of the atom, electrons move

Like planets orbiting around the sun

The glowing of a neon light is caused by electrons admitting energy as they

Move from higher to lower energy levels.

Protons and ___________ are found in the nucleus of an atom

Neutrons

If element Q has 11 protons, it's atomic ___________ is 11

Number

Neurons and __________ have almost the same mass.

Protons

What statement about subatomic particles is not true?

Protons and neutrons have the same charge

What is the difference between an atom in the ground state and an Atom in an excited state?

The atom in an excited state has more energy and is less stable than the atom in the ground state

Suppose an atom has a mass number of 23. Which statement is true beyond any doubt?

The number of protons in the nucleus does not equal the number of neutrons

What statement is true about oxygen-17 and oxygen-18?

They are isotopes of oxygen

The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

atom

The number of protons in one atom of an element is that elements

atomic number

Unlike Democritus, Aristotle did not believe that matter was composed of tiny, indivisible

atoms

Which subatomic particle has a negative charge?

electron

John Dalton concluded that all the atoms of a single _____ have the same mass.

element

An atom in which an electron has moved to a higher energy level is in a _____ state.

excited

When all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its _____ state.

ground

The subatomic particle that j.j Thomson discovered has a _______________ charge

negative

What is unique for any given element?

number of protons

The region in which an electron is most likely to be found is called a(an)

orbital

Democritus thought that matter was made of tiny particles

that could not be divided

What does the electron cloud model describe?

the most likely locations of electrons in atoms

According to John Dalton's observations, when elements combine in a compound,

the ratio of their masses is always the same