Hydrogen is unique among the elements because. 1. It is not really a member of any particular group. 2. Its electron is not at all shielded from its nucleus. 3. It is the lightest element. 4. It is the only element to exist at room temperature as a diatomic gas. 5. It exhibits some chemical properties similar to those of groups 1A and 7A. A. 1,2,3,4,5.B. 1,4,5.C. 1.2.3.5.D. 3, 4.E. 2, 3, 4, 5.

Which of the following warnings would an agricultural chemist tell a farmer who wants to recycle his or her own ammonia? recycling ammonia is a difficult process that sometimes takes weeks. recycling ammonia requires a degree in biochemistry or a related field. recycling ammonia can be harmful because it is highly flammable and toxic. recycling ammonia costs too much money considering the price of the necessary chemicals.

If a sample of radioactive isotopes takes 600 minutes to decay from 400 grams to 50 grams, what is the half-life of the isotope?

2ki + pb(no3)2 → 2kno3 + pbi2 determine how many moles of kno3 are created if 0.03 moles of ki are completely consumed.