What are elements in the same row or period called

8) 75.0 g of glucose (molar mass = 180 g/mol) is dissolved in 250 mL of solution. What is the molarity of this solution?

What volume of 1.50M NaCl contains 3.40 moles of NaCl? a) 2.27 L b) 5.10 L c) 882 mL d) 441 mL

What is the definition of valence number?

Which has a longer wave length visable or infrared

What is the pH of a solution made by diluting 1.00 mL of 0.10 M HCl with enough distilled water to make 1.00 L of solution?

Is phosphorous an atom, element, or compound

A noble gas consists of three isotopes of masses of 19.99 amu, 20.99 amu, and 21.99 amu. the relative abundances of these isotopes are 90.92%, 0.257%, and 8.82% respectively. what is the average atomic mass of this noble gas? what noble gas is this?

Adding iron filings to sand

Which of the following sets of empirícal formula, molar mass, and molecular formula is correct?

Hexane and hexene are hydrocarbon compounds from different homologous series. the combustion of these two compounds produce different amount of soot. explain the difference based on the percentage of carbon by mass.