Which electron configuration represents a selenium atom in an excited state? (1) 2-7-18-6 (2) 2-7-18-7 (3) 2-8-18-6 (4) 2-8-18-7

Who was the first to state the concept of an atom?

What are two things that happened as a blood passes the lungs?

Why are chemical reactions often carried out using solutions? The heterogenous nature of solutions prevents the reactants from freely mixing. The amount of each reactant can be controlled by adjusting the volume of each solution that is used.

For a certain process, ΔG is large and negative. Does this mean that the process necessarily has a low activation barrier? Yes No

A scientist is interested in finding out the effect of soil quality on crop quality. Would an experimental or observational study design be more appropriate?

How much MnO2 (s) should be added to excess HCl (aq) to obtain 295 mL of Cl2 (g) at 25 °C and 735 Torr?

Why do people describe water as a universal solvent

What is litmus paper used for? To indicate if all the reactants have been used up to determine if a chemical reaction has occurred to determine pH to detect the presence of water

You open your lemonade stand with 100 lemons, 5 bags of sugar containing 6 cups each, and 10 gallons of water (16 cups per gallon). Which statement is NOT true about the production of lemonade in your stand?

For the complete combustion of 5.6dm3 of a gaseuos hydrocarbon CxHy. 28.0dm3 of oxygen gas were used, 16.8dm3 of CO2 gas and 18.0gof liquid water were produced all gases measurement were made at stp. Determine the chemical formula of the hydrocarbon