A fictitious element X is composed of 25.0 percent of the isotope "x, 30.0 percent of the isotope *x, and 45.0 percent of the isotope **x. Estimate the atomic mass of element X.

Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?

The appropriate concentration for an iodine sanitizer is

Ariver current has a velocity of 5km/h relative to the shore, and a boat moves in the same direction as the current at 5 km/h relative to the river. how can the velocity of the boat relative to the shore be calculated?