Elements within a period have ___. O the same atomic number
O similar chemical properties
O the same number of electrons
O the same number of electron shells

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

Express the following number in scientific notation. 0.026890 =

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.