Aton Van Leeuwenhoek was the first scientist to discover prokaryotic organisms. These single-celled organisms lack a nucleus and other membrane bound organelles but do have a cell membrane, DNA, and even a cell wall. Choice one of the answer. A. All known living things are made up of one or more cells. B. All living cells come from pre-existing cells by division. C. A cell is the fundamental unit of structure and function in all living organisms. D. No answer text provided

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

Amixture with the same composition throughout is!

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)