Is erasing a pencil mark a chemical or physical change?

Which solution below yields the lowest final concentration of a sodium hydroxide solution prepared by diluting 50.00 mL of concentrated NaOH (19.3 M) to each of the following volumes? a. 1.15 L b. No right answer. c. 0.80 L d. 1.33 L e. 350.0 mL

Carbon-14 is particularly useful for radioactive dating. true or false?

Okay so I'm trying to understand something for my CER. I did a lab on objects that have an equal mass but volume and density vary. Now I need to defend why the volume increased and the density decreased.

Why are the bacterial endospores placed on the paper strip and not directly in the fermentation broth?

When an acid reacts with a metal, what is one of the usual products?

A chemical engineer is developing a process for producing a new chemical. One step in the process involves allowing a solution of potassium hydroxide to react with a solid. Which action would most likely increase the reaction rate for this step?

Determine which elements are balanced and unbalanced for each chemical equation below when every compound is given a coefficient of one.

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is salt and Solution B is salt. She wants to obtain ounces of a mixture that is salt.

Reactions that affect the nucleus of an atom are called? A. Fusions B. Radioactive decays C. Nuclear reactions D. Fissions

The amplitude of a wave is most directly related to what wave characteristic? Crest length Frequency Wavelength Wave height