The designations s, p, d, f designate different types of electrons. a. valence electrons. b. different electron energy levels. c. different electron orbitals within an energy level.

C

Explanation:

The electrons in an atom are specifically housed in locations that could be referred to as shells. These shells are the places where we can find an electron.

Now, within each shell, we have different energy levels in which these occupants electrons occupy. These energy levels have different energies and the amount of electrons they can take.

For example, the number of electrons S can take is 2 while that in which d can take is 10

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j