Exam 2: Atoms, Elements, and Minerals

The softest mineral on Mohs' hardness scale is ____.

Plagioclase feldspar commonly exhibits __, straight, parallel lines on the flat surfaces of one of the two cleavage directions.

Five of the six minerals collectively known as asbestos contain single chains of silica tetrahedral and belong to the _______.

In some minerals the bonds are equally strong in all directions, therefore they have no cleavage but instead _____ along irregular surfaces that are commonly curved.

_____ is the ability of a mineral to break, when struck or split, along preferred planar directions.

The atomic mass number of common oxygen is 16 because it has ___ protons and ___ neutrons.

_______ of an element are atoms containing different numbers of neutrons but the same number of protons.

A silica tetrahedron is composed of four atoms of the element ___ and one atom of __.

The third most abundant element in the Earth's crust is ______; it is more common than iron.

The mineral ___ reacts with weak hydrochloric acid to produce carbon dioxide gas, i.e., it effervesces (fizzes) in dilute acid.

All of the most common rock-forming minerals in Earth's crust are silicate minerals.

The hardest mineral has a hardness of ___ on Mohs' relative hardness scale.

Carbon-14 has eight __.

A mineral specimen with a Mohs hardness of 5 can scratch a mineral specimen with a hardness of 3.

____ is the most common element in the Earth's crust.

____ elements make up 98% of the Earth's crust.

The mineral ___ is an example of a native element.

The crystal form of a mineral is a set of faces that have a definite geometric relationship to one another.

The atomic mass number of an atom is the total number of ___ in the atom.

Specific gravity is the ratio of the mass of a mineral to the mass of an equal volume of __.