<span>Safety glasses are to be worn whenever working with acids, bases, or any flammable materials. Let the instructor know immediately about any glassware breakage or chemical spills that may occur so that proper cleanup procedures can be instituted.Use pipet fillers whenever pipeting any fluid.Whenever working with acids or bases, have the chemicals available at your work station, do not carry pipets with fluid across the room.When diluting acids, pour the acid into the water, NOT water into acid as this may cause spattering of the acid.When acid is mixed with another reagent, an exothermic reaction may occur which heats up the container, This is natural, so do not panic and spill contents.All volatile materials must be handled in a hood with the exhaust fan on.When refluxing any solutions, perform this operation under a hood, and use boiling beads in the reflux vessel to prevent any excessive "bumping" and possible glass breakage.Use heat-resistant gloves and/or tongs when handling hot glassware, chinaware, etc.Use plastic gloves when handling any hazardous materials to prevent skin contact.Label and date all chemical mixtures that are made up and kept for future use.Do not store basic solutions in glass containers with glass stoppers, use plastic or rubber stoppers.Dispose of all used solutions in an approved manner as directed by the instructor.Empty all used inoculated bacteriological media from test tubes or dishes into a designated container so that it may be sterilized before disposal.Before leaving, turn off all power and heat to the apparatus you have used, or place in the standby mode.Clean all spatulas, glassware, and dishes after use and before storage to prevent contamination.<span>Return all chemicals you are using to their proper storage space.Be familiar with the use of the eye-wash, the laboratory shower (if equipped), and the first-aid kit if they are needed at any time.</span></span>
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
B an extrusive igneous rock
