Use the following information to answer the next question. Diboron trioxide, B203(s) has many uses including being used as an additive in the production of fibre optic cables. The following reactions can be used in the synthesis of diboron trioxide. H;BO3 (aq) → HB0,(aq) + H2O(1) A,H = +0.4kJ H, B407 (aq) + H,0(1) → 4HBO2 (aq) A,H = -12.1kJ H, B40, (aq) → 2B2O3(s) + H2O(1) A,H = +17.9kJ Using the information above, the enthalpy change for the following reaction 2H3BO3 (aq) → B,0;(8) + 3H2O(1) is calculated to be kJ. Record your 3-digit answer. Include sign, do not include units.

Introduction of the periodic table: Give a timeline outlining who contributed to the discovery of the periodic table. Explain how the elements are arranged in the periodic table. What are groups and periods? How many groups and periods are in the periodic table?

Question 20

Question 14 Infrared radiation has lower energy than visible radiation. O True False