PLEASE HELP I DON'T KNOW THIS QUESTION I NEED HELP!! Two students below described a type of Earth's outermost layer:

Student A: 512 kilometers deep
Student B: Makes up the sea floor

Which type of outermost layer did the students describe?

A.) They both described the oceanic type.
B.) They both described the continental type.
C.) Student A described the oceanic type and Student B described the continental type.
D.) Student A described the continental type and Student B described the oceanic type.

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.