1. The diagram shows a box that is sliding down a ramp F1
F4
F2
F3
Which arrow correctly indicates the direction of friction acting on the box?
A F1
B. F2
C3
D. 14

10 POINTS!!!

the answer is B.F2 because it's indicates the direction

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.