Niobium-91 has a half-life of 680 years. After 2,040 years, how much niobium-91 will remain from a 300.0-g sample?

3 g

18.75 g

37.5 g

100.0 g

A model is any representation of an object or

Identify the limiting reactant in the reaction of iron and chlorine to form FeCl3, of 22.7 g of Fe and 37.2 g of Cl2 are combined. Determine the amount (in grams) of excess reactant that remains after the reaction is complete.

Which step of scientific inquiry involves organizing and interpreting the data? a. Experimentation b. Analysis c. Conclusion d. Hypothesis

Do hydrogen atoms and chloride ions form hydrogen bonds? Why?

What occurs at one of the electrodes in both an electrolytic cell and a voltaic cell?

Based on the kinetic molecular theory, which of the following statements is correct about the particles in a sample of gas? They have negligible kinetic energy. There is negligible force of attraction between them.

The greenish color of plant cells comes from a. the cell membrane b. chloroplasts c. ink

Describe what might happen to the water cycle if less solar energy reaches Earth and how Earths climate would be affected.

In addition to canyons, what other kinds of geologic formations might separate similar organisms

Iron has a density of 7.86 g/cm3. Calculate the volume (in dL) of a piece of iron having a mass of 4.79 kg.