Which of the following elements is the most reactive?

Chlorine

Bromine

Fluorine

Helium

What information is needed to determine the energy of an electron in a many-electron atom? Check all that apply.

The density of a sample of gasoline is. 70g/cm. what is the mass of 1 liter of this gasoline

Digoxin injection is supplied in ampules of 500 mcg per 2 mL. How many milliliters must a nurse administer to provide a dose of 0.2 mg? img20. img 0.5 mg-2 Sooring = 0r5mg 0 12mg = x 0.001X500mcg = 0.5 mg 0,2 mg x 2mL = 0.8mL 0.5 m

What is the mole ratio of AlCl3 to AlSO4 in the above chemical reaction?

Add the following thermochemical equations: (1) P4 (s) + 6Cl2 (g) = > 4PCl3 (g) ΔH = - 1148 kJ (2) 4PCl3 (g) + 4Cl2 (g) = > 4PCl5 (g) ΔH = -460 kJ (3) Overall equation = ? ΔHoverall = ? Select the correct ΔH for the overall process (equation 3)

Which physical method can be used for obtaining a sample of salt from a small beaker of salt water? boiling freezing chromatography sorting

Science is a unique field of thought because it relies on to describe the world. •Observations and experim •Teachers and students •Books and writings •Scientists and statements

Hemoglobin, a protein in red blood cells, carries o2 from the lungs to the body's cells. iron (as ferrous ion, fe2+) makes up 0.33 mass % of hemoglobin. if the molar mass of hemoglobin is 6.8 Ã 104 g/mol, how many fe2 + ions are in one molecule?

What could you predict about a methane molecule that would most likely be made by using both the quantum model of the atom and John Dalton's model?

What is the molar mass of an unknown hydrocarbon whose density is measured to be 1.97 g/l at stp?