Which of the following is a pure substance that can be separated by physical means and can't be decomposed into other substances by chemical means

A: element

B:molecule

C: compound

D: mixture

When the radioactive isotope of Th-234 emits a beta particle to become Pa-234, it also loses a small amount of mass which is emitted as A) a positron. B) gamma radiation. C) an alpha particle. D) ultraviolet radiation.

Which term refers to the speed at which reactants are converted into products?

In a chemical formula such as C6H12O6 and H2O, what do you call the little numbers below the normal line of text. subscript number, superscript numbers

Which statement describes a scientific theory? A. A theory states how something behaves without explaining why. B. A theory is a proven fact that cannot be changed. C. A theory changes based on new observations and testing. D.

What is the number of magnesium atoms that equal a mass of 24.31 amu?

How many particles are in 3.55 moles of Aluminum Sulfate

Major geological events that occur when plates shift suddenly and released stored energy: A. Volcanic eruptions B. Earthquakes C. Antarctic plate D. Spreading ridges

How does a salt bridge improve a battery

Hat information is needed to determine the energy of an electron in a many-electron atom?

Write the formulas for the following compounds: (a) copper (l) cyanide, (b) strontium chlorite, (c) perbromic acid, (d) hydroiodic acid, (e) disodium ammonium phosphate, (f) potassium dihydrogen phosphate, (g) iodine heptafluoride, (h)