Of the four atoms, Ge, Ca, S, Si ____ is the most electronegative.

Calculate the wavelength (in meters) of a radiation that has a frequency of 1.25 × 1014 Hz.

Calculate the molar mass of this compound: C9H8O7

The density of potassium is 0.86 g/cm3 (or 0.86 g/mL). What is the volume, in mL of 0.50 kg of potassium (pay attention to kg vs. g)?

Consider the combustion reaction shown below:                                                         2 C8H18(l) + 25 O2(g) ——–> 16 CO2(g) + 18 H2O(l) Using standard heats of formations given below, calculate

Which is expected to have the highest surface tension at 25 °C?

The number of lone pairs of electrons around the central atom in SbCl3 is:

The electron configuration of oxygen atom is:

Which isotope has 36 electrons in an atom? 

Consider the reaction: 2 N2(g) + 5 O2(g) ——->  2 N2O5(g) How many grams of O2 are required to react with 70 grams of N2?