Which of the following pairs of elements are chemically most similar to each other?

A. K and Ca

B. C and Si

C. N and O

D. Sn and As

Why are nh3 and ch3nh2 no longer nucleophiles when they are protonated?

Match the term with its description. Match Term Definition Colloid A) A mixture in which two or more liquids are mixed that normally are not mixable Emulsion B) Mixture that has its different components mixed evenly within the substance

Diamond and graphite are two crystalline forms of carbon. In which form are the bonds between the C atoms arranged at tetrahedral angles to each other? a. diamond b. Neither of these c. graphite

25. The periodic table is based on an element's A. atomic number. B. molecular size. C. molecular mass. D. atomic mass.

Define thermometer and degree

Consider the two electron arrangements for neutral atoms A and B. What is the difference between atom A and atom B? A - 1s22s22p63s1 B - 1s22s22p65s1 Atom B has lost some inner electrons.

Choose all the answers that apply. Which of the following has kinetic energy? rolling ball, moving car, book on a table, spinning top, or a falling tree.

Which of the following statements about the suns feature is true?

Preteins vary widely in structure, whereas nucleic acids have rather uniform structures. How do you account for this major difference?

Convert the pressure 0.840 atm to mm Hg