In an electron dot diagram, the symbol for an element is used to represent
a. the nucleus.
b. the nucleus and all electrons.
c. the nucleus and valence electrons.
d. the nucleus and all non-valence electrons.

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

Anybody wanna ? (picture included? )

=force × distance a. work b. velocity c. pressure d. momentum