Chapter 3

Who first proposed an atomic theory based on scientific knowledge?

• John Dalton

• Jons Berzelius

• Robert Brown

• Dmitri Mendeleev

According to Dalton's atomic theory, atoms

• are destroyed in chemical reactions

• can be divided

• of each element are identical in size, mass, and other properties.

• of different elements cannot combine.

Tags

NGSS.HS-PS1-7

Which of the following is NOT part of Dalton's atomic theory?

• atoms cannot be divided, created, or destroyed

• the number of protons in an atom is its atomic number

• in chemical reactions, atoms are combined, separated, or rearranged

• all matter is composed of extremely small particles called atoms

Tags

NGSS.HS-PS1-7

The law of definite proportions

• contradicted Dalton's atomic theory

• was explained by Dalton's atomic theory

• replaced the law of conservation of mass

• assumes that atoms of all elements are identical

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

• nuclide

• neutrons

• electron

• isotope

Tags

NGSS.HS-PS1-8

The nucleus of most atoms is composed of

• tightly packed protons

• tightly packed neutrons

• tightly packed protons and neutrons

• loosely connected protons and electrons

Protons and neutrons strongly attract when they

• are moving fast

• are very close together

• are at high energies

• have opposite charges

An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is

• 13

• 14

• 27

• 40

Tags

NGSS.MS-PS1-1

Isotopes are atoms of the same element that have different

• principal chemical properties

• masses

• numbers of protons

• numbers of electrons

Atoms of the same element that have different masses are called

• moles

• isotopes

• nuclides

• neutrons