What information does an empirical formula give? A. The ratio of the atoms in a molecule as found in nature B. The lowest whole-number ratio of atoms in a molecule C. The order in which atoms are bonded in a molecule D. The percent composition of atoms in a molecule

(b) Calcium and fluorine

Consulta la tabla periódica que se encuentra en el apéndice 1 de tu libro de tex o identifica si los siguientes conjuntos de elomentos forman parte de un poriod un grupo o ninguno. Unelos con una llnea. \( \begin{array}{l}\text { a) } \mathrm{Li}, \mathrm{Na}, \mathrm{K}, \mathrm{Rb} \\ \text { beriodo } \\ \text { br } \mathrm{Sr}, \mathrm{Ag}, \mathrm{Cd} \\ \text { c) } \mathrm{Fe}, \mathrm{Co}, \mathrm{Ni}, \mathrm{Cu} \\ \text { d) } \mathrm{He}, \mathrm{Ne}, \mathrm{Ar}, \mathrm{Xe} \\ \text { e) } \mathrm{S}, \mathrm{Se}, \mathrm{Te}, \mathrm{Po}\end{array} \quad \) Ninguno

Nobelium-259 is a radioactive substance that decays according to the following function, where \( y_{0} \) is the initial amount present, and \( y \) is the amount present at time \( t \) (in minutes). \[ y=y_{0} e^{-0.0119 t} \] Find the half-life of Nobelium-259. Do not round any intermediate computations, and round your answer to the nearest tenth.

A cave with beautiful prehistoric wall paintings was discovered. Some charcoal found in the cave contained \( 29 \% \) of the \( { }^{14} \mathrm{C} \) expected in living trees. How old are the cave paintings? (The decay constant for \( { }^{14} \mathrm{C} \) is .00012 .) The cave paintings are \( \square \) years old. (Round to the nearest year as needed.)

3. Write the chemical formula for the following compounds, given their constituent elements. (a) Copper(I) and oxygen