Life on Earth evolved based on the element carbon. Based on periodic properties, what two or three elements would you expect to be most like carbon?

Potassium is a highly reactive metal while argon is an inert gas. Explain this difference based on their electron configurations.

Sketch the given region R and then find its area. R is the region bounded by the curve $y=\frac{1}{x^{2}}$ and the lines y = x and $y=\frac{x}{8}.$

Arrange these elements in order of increasing metallic character: Fr, Sb, In, S, Ba, Se.

Both vanadium and its 3+ ion are paramagnetic. Refer to their electron configurations to explain this statement.

Suppose you were trying to find a substitute for $Na^+$ in nerve signal transmission. Where would you begin your search? What ions would be most like $Na^+$? For each ion you propose, explain the ways in which it would be similar to Na+ and the ways it would be different. Use periodict rends in your discussion.

Choose the element with the more negative (more exothermic) electron affinity from each pair. a. Mg or S, b. K or Cs, c. Si or P, d. Ga or Br.

Choose the element with the higher first ionization energy from each pair. a. P or I, b. Si or Cl, c. P or Sb, d. Ga or Ge.

Which pair of elements would you expect to have the most similar atomic radii, and why? a . Si and Ga, b. Si and Ge, c. Si and As.

Find and simplify the expression if $f(x)=x^{2}-4$. $f(2)+f(h)$

1. Es imposible (1.) el futuro, pero no hay duda de que (2.) de la tecnología va a aumentar. Cada día, los ingenieros de sistemas escriben programas que cambian nuestra vida. Claro, las computadores nunca van a (3.) a las personas, pero (4.) como (5.), muestran cómo una computadora puede funcionar (6.) una persona. Pero con todos (7.) en (8.) de la informática, es importante (9.) que las computadoras nunca serán personas.

You read a science fiction story about an alien race of silicon-based life-forms. Use information from the periodic table to hypothesize why the author chose silicon over other elements. (Hint: Life on Earth is carbon based.)

True or False. The notation $a_{5}$ represents the fifth term of a sequence.

Which experience a greater effective nuclear charge: the valence electrons in beryllium or the valence electrons in nitrogen? Why?