An element to use to fill bottles that contain ancient paper the element to be a gas at room temperature should be denser than helium and should that not easily react with other chemicals

A sample of hydrated copper (II) sulfate has a mass of 4.56 g. After heating, it has a mass of 2.92 g. What is the percent by mass of water in the hydrate?

What compound does the formula NO2 represent? nitrogen oxide nitrogen dioxide dinitorgen oxide nitroxide

Which activity involving a segment of DNA does not result in a mutation? Adenine is added to the sequence. Thymine and guanine are removed. mRNA pairs adenine with uracil instead of thymine. mRNA substitutes guanine for adenine in two locations.

What are the disadvantages and advantages of alloys?

3.95x10^25 atoms Cu2S to grams

How does protein substance in an animal hide or skin be prevented from bacterial infection during the process of tanning? * a. By soaking in water b. By deliming using an acid c. By brine curing d. By scudding with dull knife

Nonpolar materials have separated positive and negative areas. True False

Large rocks being blasted to make way for the construction of a tunnel is an example of what type of weathering? A. Chemical B. Mechanical C. Deposition D. Erosion

A criminalist uses a fluorescent chemical called rhodamine, cyanoacrylate fumes, and a uv light source to see a fingerprint on a gun. Which type of evidence is he detecting? Gross evidence latent evidence direct evidence trace evidence

Which of the following energy changes occurs as a ball bounces