What are the element represented by [He]2s2

What volume of a 0.580-m solution of cacl2 contains 1.28 g solute?

Water seeps into cracks in a rock, expands on freezing, and enlarges the cracks in a process called A. exfoliation B. Hydrolysis C. Frost Wedging D. Frost heaving

Ms. Sullivan's class is designing a miniature roller coaster. After first setting it up, they find that it didn't have enough speed to go through the loop de loop.

Cu has an anomalous electron configuration. write the observed electron configuration of cu.

How many electrons are in the 2p sublevel of nitrogen?

What is an isotope? Give an example of an element with isotopes.

Consider the reaction between liquid water and aqueous magnesium nitride to form solid magnesium oxide and ammonia gas. If magnesium nitride is present in excess, how many moles of water are needed to form 9.17*1023 ammonia molecules?

The properties of elements are arranged by ... A. mass numbers B. atomic masses C. atomic radii D. atomic numbers

When a tire is inflated with air is it a chemical or physical change?

Which isotope is used to date ancient artifacts such as fossils? carbon-12 carbon-14 uranium-238 oxygen-16