Zirconium has an atomic number of 40 and an atomic mass of 91. How many neutrons does it have? A. 40 B. 51 C. 91 D. 131

Drinking water may contain a low concentration of lead ion (Pb2) due to corrosion of old lead pipes. The EPA has determined that the maximum safe level of lead ion in water is 15 ppb.

How many moles are there in 15.0 grams of SiO2? a 0.170 mol b 0.340 mol c 0.534 mol d 0.250 mol e 0.208 mol Check it

Which statement correctly describes a physical change? involves breaking and creating chemical bonds but not changing a phase may involve a change in phase but does not involve a change in the molecular structure may involve converting two or more

When a certain isotope such as Pu-239 is hit by a neutron it will always split into the same smaller nuclei. A. True B. False

Starting with precipitation, list the order of the steps of the water cycle.

Consider the compound Sn (SO4) 2 and answer the following questions: a. What is the name of this compound? b. What is the molar mass of this compound? Explain how you calculated this value.

If you put a base in water, what will happen? A. it will dissociate B. it will form a covalent bond. C. it will bond with the water molecules

What is the definition of tone?

Which abiotic factor differentiates between the three major types of aquatic biomes? (freshwater, estuary, marine) Question 4 options: sunlight movement salinity oxygen

What's is the percent composition by mass of oxygen in magnesium oxide, Mg0