1. Fill in the timeline to identify some important moments in the history of the development of the periodic table
Scientists used the periodic table to:
Chemists had
described almost
The number of
known elements
elements.
is
Mid-1800s
Early 1900s
Today
2. Complete the sentence.
Elements with similar
are located near one another in clusters in the periodic table.
3. Fill in the chart to identify three pieces of information given in each square of the periodic table.

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

3.) for each of the following compounds, draw the major organic product of reaction with hcl or naoh and circle whether the starting materials and products will be more soluble in organic solvent or water benzoic acid + hcl: benzoic acid + naoh: oh benzoic acid water/organic water organic fluorenone hс: fluorenone + naoh: fluorenone water/organic water/organic веnzocaine + hci: benzocaine + n»oh: h2n benzocaine water/organic water organic o=