CHEMISTRY FALL 2024 EXAM REVIEW

According to Dalton's atomic theory, atoms

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

• can be divided into protons, neutrons, and electrons.

• of all elements are identical in size and mass.

• can be destroyed in chemical reactions.

Tags

NGSS.HS-PS1-7

Dalton's theory essentially agreed with the present atomic theory EXCEPT for the statement that

• all matter is made up of small particles called atoms.

• atoms are not divided in chemical reactions.

• atoms of the same element are chemically alike.

• all atoms of the same element have the same mass.

Tags

NGSS.HS-PS1-7

The behavior of cathode rays produced in a glass tube containing gas at low pressure led scientists to conclude that the rays

• were not composed of matter.

• were composed of positively charged particles.

• were composed of negatively charged particles.

• were composed of uncharged particles.

Tags

NGSS.HS-PS2-5

Because most particles fired at metal foil passed straight through, Rutherford concluded that

• atoms were mostly empty space.

• atoms contained no charged particles.

• electrons formed the nucleus.

• atoms were indivisible.

Because a few positively charged particles bounced back from the foil, Rutherford concluded that such particles were

• striking electrons.

• indivisible.

• repelled by densely packed regions of positive charge.

• magnetic.

A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n)

• nuclide.

• neutron.

• electron.

• isotope.

Tags

NGSS.HS-PS1-8

The nucleus of an atom has all of the following characteristics EXCEPT that it

• is positively charged.

• is very dense.

• contains nearly all of the atom's mass.

• contains nearly all of the atom's volume.

Tags

NGSS.HS-PS1-8

Protons within a nucleus are attracted to each other by

• nuclear forces.

• opposite charges.

• their energy levels.

• electron repulsion.

An atom is electrically neutral because

• neutrons balance the protons and electrons.

• nuclear forces stabilize the charges.

• the numbers of protons and electrons are equal.

• the numbers of protons and neutrons are equal.

Isotopes are atoms of the same element that have different

• principal chemical properties.

• masses.

• numbers of protons.

• numbers of electrons.