When a sample of rust was mixed with acid, the rust changed into two simpler substances: W and Z. The substances W and Z could not be broken down into simpler substances. A. The substances W and Z are compounds. B. Rust is a compound made of two elements. C. The substances W and Z are not made of atoms. D. Rust is an element that breaks into compounds.

B. Rust is a compound made of two elements.

Explanation:

A substance is a form of matter which has a constant composition and distinct properties. Depending on whether they can be separated by chemical means or not, they can be compounds or elements, respectively.

The problem tells us that a sample of rust, after a chemical reaction with acid, is separated into two simpler substances W and Z. Therefore, the rust is a compound.

After obtaining W and Z, these substances can not be broken down into simpler substances. Therefore, these substances are elements.

Rust is a compound made of two elements, iron and oxygen.

i think it is d. e because the next one is igneous.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).