Which of the following attain the linear structure (i) BeCl2 (ii) NaCO+ (iii)NO2 (iv) NO2-

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Can someone me with 1 to 4 plz. fast