The element boron (B, atomic number 5 and atomic mass 11) is right above aluminum (Al, atomic number 13 and atomic mass 27) in the periodic table. How many more electrons does aluminum have than boron? Why?

In science, all concepts are a) opinions and facts. B) beleifs that are familiar and complicated. c) testable and observable. D) theories that cannot be proven.

As seen from earth how long does it take the moon to rotate on its axis?

A ball that has a mass of 0.25 kg spins in a circle at the end of a 1.6 m rope. The ball moves at a tangential speed of 12.2 m/s.

Which was a testable idea that Ernest Rutherford developed in his experiments? - The positive charge in an atom is concentrated in one location. - Atoms are not divisible into smaller particles. - It is impossible to define the mass of an atom.

The x-coordinates of two objects moving along the x-axis are given as a function of time t. x1 = (4 m/s) t and x2 = - (159 m) + (24 m/s) t - (1 m/s2) t2. Calculate the magnitude of the distance of closest approach of the two objects.

If you double the radius of the earth and keep the mass of the earth the same, the acceleration of gravity on the surface of the earth will be approximately ...

In an electron dot diagram the symbol for an element is used to represent

The space shuttle undergoes an acceleration of 53.9 m/s2. How fast is it traveling at the end of 55.2s

Which of the following has the greatest amount of kinetic energy a) slice of pizza b) a person at the top of the stairs c) wind d) a book on a table

Physical properties within a period are more alike than physical properties within a group. True false