Fluorine gas is placed in contact with calcium metal at high temperatures to produce calcium fluoride powder. What is the formula equation for this reaction?

What is the frequency of a wave with a wavelength of 6.40x10^4 meters?

Which element is an alkali metal?

A nurse practitioner prepares an injection of promethazine, an antihistamine used to treat allergic rhinitis. If the stock bottle is labeled 25 mg/mL and the order is a dose of 11.0 mg, how many milliliters will the nurse draw up in the syringe?

Why can we expect bigger storms during a cold front rather that a warm front

Current atomic models show an atom's nucleus surrounded by electron clouds. An electron cloud is a region around an atom's nucleus where an electron is likely to be. Which of the following is a limitation of current atomic models? A.

Which impurity can bioaccumulate in aquatic systems? A. Mercury B. Sulfur C. Carbon Dioxide D. Methane

What is the element K2SO4 and is it ionic, covalent or polyatomic

The elements in a star can be determined by analyzing the star's spectrum. Which statement explains why no two elements have the same spectrum? A. Each element has a unique arrangement of electrons. B.

What's the difference between cation and an anion

Where does the largest percent of water exist on Earth?