Based on this cell from the periodic table, which statement is true for the element magnesium?

A. A magnesium atom contains 12 protons, and neutral magnesium
atoms contain 24 electrons.
B. A magnesium atom contains 12 protons, and most magnesium
atoms contain 12 neutrons.
C. The atomic number of magnesium is 24.3, and its atomic mass is
12
D. The atomic number of magnesium is 12, and its average atomic
mass is 12

Select the word from the list that best fits the definition classification of most stars on the h-r diagram

Three charge are arranged as shown in the diagram. the magnitude of the net electrical force acting on the +6 uc charge, rounded to the tenths place, is .

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".