On a statistical basis, smoking a single cigarrette lowers your life expectancy by 642,000.Pls answer this question

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Given the following reaction: c3h8+5o2=3co2+4h20 how many grams of co2 will be produced 7 g of c3h8 and 98 g of o2

What makes up a film badge? layers of photographic film covered in black paper. an electrolyte paste spread across a plastic sheet. a thin film of salts and other chemicals on clear acetate. a panel of photographic film exposed to the air. ✓