A gravel can be broken down into different kinds of substances by physical processes. No chemical reactions are needed to separate different parts of gravel into pure substances. This is because gravel is a(n)

O compound
O element
O homogeneous mixture
O heterogeneous mixture

Select the correct answer. which statement is true about a polarized object? o a. it gains electrons and becomes negatively charged. ob. it gains protons and becomes positively charged. oc. the number of positive and negative charges can be the same. od. it has to be a metal. o e. there is no change in the distribution of the charge in the object. reset next what

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

Write the formula for the following chemicals. 7. e. trinitrogen tetraoxide a calcium phosphate f. magnesium acetate b. potassium sulfide g nickel(iii) cyanide c carbon dioxide h. silver sulfate d. cobalt(ii) chloride