If the half-life of a radioactive substance is 600 years, what fraction of the original material is left after 1,800 years?

What type of bond has a repeating pattern of positive and negative ions?

Consider the evaporation of methanol at 25.0∘c: ch3oh (l) →ch3oh (g). you may want to reference (pages 826 - 829) section 18.9 while completing this problem. part a part complete find δg∘ at 25.0∘c.

Which statement explains how commercial land use negatively impacts watersheds? Chemicals in fertilizers run off into water and cause algae blooms. Production of clothing items makes pollutants that contaminate the water.

A model of an atom is shown below. Which element is represented by this model of an atom? Boron, Carbon, Neon, or Sodium?

How might a scientist confirm the result of other experiments by doing an experiment?

Four properties of water are listed. 1. It is colorless and odorless in its pure form. 2. It reacts with metals to form metal hydroxide and hydrogen gas. 3. When heated to 100 °C, water evaporates. 4. It decomposes to form hydrogen and oxygen.

Water is A. Acidic B. Basic C. Neutral

What variables affect the acceleration of an object and in what manner do they affect the acceleration?

How do valence electrons relate to the chemical reactions of an element?

What is the weighted-average mass of all known isotopes for an element