Which determines how atoms combine to form molecules?
a: the number of protons
b: the number of electrons
c: the arrangement of electrons
d: the configuration of electron shells
e: all of the above

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

For questions 1 and 2, consider the following experimental data.hydrogen emission lines were detected at the following wavelengths (in nm): 121.6102.697.395.093.8question 1use the electromagnetic radiation classifications below and figure 1-1 in the introductory information for this lab (in the lab manual) to determine the nf value for the experimental data provided? wavelength, ? (nm) 650 700 550 600 400 450 500 visible spectrum wavelength, ? (m) 11 10 3 10 10 10 8 10 5 10 10 -10 10 9 10 10 10 10 -12 10 microwave radio infrared x-ray ultraviolet gamma 1020 1019 1018 1 1016 015 1014 01 12 109108 frequency, v (hz)a.1b. 2c. 3d. 4e. 5question 2using the data for the emission line with the longest wavelength, the known value of nf (from question 1 in this prelab), and the value of ni (deduced from the ? and nf values) calculate the rydberg constant for hydrogen (rh) in units of m-1.a) 1.097 x 10-11 m-1b) 5.921 x 107 m-1c) 1.097 x 10-2 m-1d) 9.252 x 106 m-1e) 1.097 x 107 m-1

1.17 mol hcl and 2.5 mol naoh react according to the equation hcl + naoh -> nacl + h2o . if the limiting reactant is hcl, determine the amount of excess reactant that remains. answer in units of mol.