The concentration of calcium in a cell is 3%. the concentration of calcium in the surrounding fluid is 1%. how could the cell obtain more calcium?

In the past earths sea level has sometimes been lower at that time which of the following would have been a major difference in the ocean basins

Can someone explain to me about Phlogiston and what Antoine Lavoisier proposed?

In which compound do atoms form bonds by sharing electrons A) H2O B) CaO C) Na2O D) MgO

A sound wave from a jackhammer travels through a section of concrete with a fixed frequency. At the concrete's boundary is mud. The diagram below shows the path of the sound wave as it travels from the concrete into the mud.

What percentage of water vapour is in the air?

A 20.0 mL sample of a NaCl solution has a mass of 21.040 g. After the solution is evaporated to dryness, the dry salt residue has a mass of 4.348 g. Calculate the following concentrations for the NaCl solution.

What are the intermolecular forces present in Argon?

What characteristic is shared by most simple polyatomic ions? A) They are anions. B) They are bonded ionically. C) They are cations. D) They have positive charges.

Potassium ions (k+) have a positive charge. What happens to a potassium atom electrons when it becomes an ion

At what pH do you think acids become too dangerous to touch? Basis? Explain your answers.