Unit 2 Structure of Atoms, Isotopes, TPT and Ions

Why do atoms of elements have neutral charges?

• all atoms contain neutrons, which have no charge.

• the number of protons and the number of neutrons are equal

• the number of protons and the number of electrons are equal

• the number of neutrons and the number of electrons are equal

Which subatomic particles account for most of the mass in an atom?

• electrons

• protons

• protons and neutrons

• neutrons and electrons

Which of the following determines the identity of an element?

• the number of protons

• the number of neutrons

• the number of energy levels

• the arrangement of electrons

A carbon atom has an atomic number of 6 and a mass number of 12. A student wants to make a model showing the energy levels of this atom. How would the student place the electrons in the model?

• four electrons in the energy level closest to the nucleus and two electrons in the second energy level.

• two electrons in the energy level closest to the nucleus and four electrons in the second energy level.

• six electrons in the energy level closest to the nucleus and six electrons in the second energy level, and six electrons in the third energy level.

• two electrons in the energy level closest to the nucleus and eight electrons in the second energy level, and four electrons in the third energy level.

Tags

NGSS.MS-PS1-1

A subatomic particle is removed from an atom to form an ion. A student wants to draw a diagram of this process. From which part of the atom should the student show the subatomic particle being removed?

• from the nucleus of the atom

• from the inner part of the atom

• from the innermost energy level of the atom

• from the outermost energy level of the atom

An isotope of chlorine has 17 protons and 19 neutrons. What is the mass number for that isotope of chlorine?

• 2

• 17

• 19

• 36

Francium is an element found in group 1 and period 7. How many valence electrons does an atom of Francium contain?

• 1

• 6

• 7

• 8

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Sodium is an element found in group 1 and period 3. What kind of ion is a sodium most likely to form?

• 7-

• 1-

• 1+

• 7+

Iodine is a halogen found in group 17 and period 5. How many valence electrons does iodine have?

• 5

• 6

• 7

• 17

Which category of elements is most likely to form negative ions?

• halogens

• transition elements

• alkali metals

• main group