Aballoon containing helium gas expands from 230 ml to 860 ml as more helium is added. what was the initial quantity of helium present if the expanded balloon contains 3.8 × 10-4 mol, assuming constant temperature and pressure? which of the variables are known?

This chart represents the melting point of several substance. what besy explains the high melting point of the salt?

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

Which of the following is true about a carbonated soft drink? . the carbon dioxide is the solvent, and water is the solute.. the water is the solution, and carbon dioxide is the solvent.. the carbon dioxide is the solution, and the water is the solvent.. the water is the solvent, and the carbon dioxide is the solute.. .