10 The book will serve as a flat surface on which you
will later place additional weights. It has its own
mass, which you need to measure,
Zero the balance. Place the book on the balance.
Measure the mass to the nearest gram (1 g).
g

497.680g 270

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

b.

the accuracy of the data.