A fictitious element X is composed of 10.0 percent of the isotope 55X, 20.0 percent of the isotope 56X, and 70.0 percent of the isotope 57X. Calculate the weighted atomic mass of element X to the nearest tenth.

At their centers, all the jovian planets have cores made of: new elements produced by the high pressure;

A typical virus is 5x10-6 cm in diameter. if avogadro's number of these virus particles were laid in a row, how many kilometers long would the line be?

2. Describe in a step by step manner how you determined the identity of the two unknowns. Discuss both what you determined the unknowns to be and the method that you used to find them.

How do you measure one wavelength?

During the day, water from the ocean is transferred to the atmosphere. Which of the following describes the energy change that takes place during the transfer? Energy is transported from the ocean to the atmosphere which makes the atmosphere warmer.

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?