Sodium has an atomic number of 11 and has a net charge of 0. when sodium combines with chlorine, it has a net charge of +1. why?

Will mark brainliest 26. which of these statements are true? (3 points) a. gases are compressible b. gases fill their containers completely c. the pressure of a gas is independent of the temperature d. gases have mass e. gases exert pressure f. the pressure of a gas is dependent on the volume g. gas pressure results from the collisions between gas particles h. gases have a definite volume and shape

Compare and contrast physical changes with chemical changes.

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.