Three experiments were run starting with different initial amounts of n2o4(g) ([n2o4]0 in the table). the systems were allowed to reach equilibrium and the concentrations for each gas were measured (in units of moles/liter). for each of the boxes below, calculate the ratios indicated by the column heading. this will show the mathematical relationship that exists between the concentrations of no2 and n2o4 at equilibrium. be sure to round to the correct number of significant figures. exp [n2o4]0 [no2] [n2o4] [no2] / [n2o4] 2 [no2] / [n2o4] [no2]2 / [n2o4] 1 3.5 2.85 2.1 2 3.0 2.56 1.7 3 2.6 2.33 1.4 based on your calculations, indicate whether each statement is true (t) or false (f): 1. each experiment started with a different initial concentration of n2o4. 2. the ratio ([no2] / [n2o4]) is equal to a constant value. 3. the ratio (2 [no2] / [n2o4]) is equal to a constant value. 4. the ratio ([no2]2 / [n2o4]) is equal to a constant value. 5. each experiment reached a different set of equilibrium concentrations.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.