2. Which of the following is the best example of a closed system? (2 points)
O
An unsealed beaker
O
Our universe
O
A sealed glass flask
O
An insulated gas cylinder

In a ni-cd battery, a fully charged cell is composed of nickelic hydroxide. nickel is an element that has multiple oxidation states. assume the following proportions of the states: nickel charge proportions found 0 0.17 +2 0.3 +3 0.33 +4 0.5 (a) determine the mean of the nickel charge. enter the answer to 2 decimal places.(b) determine the cumulative distribution function of nickel charge.

Draw the lewis dot structure for each of the following polyatomic ions

Which is true about metals used for jewelry, such as platinum and gold? a. they have low flammability. b. they have low reactivity. c. they have high flammability. d. they have high reactivity.