Please help! What frequency of sound wave does boat sonar use? A. kilowatts B. electromagnetic C. ultrasound D. infrasound

Why are the trends and exceptions to the trends in ionization energy observed?

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d

For each of the following types of reactions, write a general reaction formula in the symbolic form—for example, a + b → ab. single-displacement double-displacement synthesis decomposition