Another hypothesis about the mass extinction 66 million years ago involves a supernova happening near earth. this could have produced enough iridium to explain the anomaly. however, the supernova would have also led to two other results that were unlikely. describe one of the possible results from the supernova hypothesis that was not supported by the fossil record or the iridium layer.

Janel’s class studied properties of matter and how matter can change. janel decided she would do an experiment mixing baking soda and vinegar. question: describe the properties of baking soda and vinegar, and explain the changes that janel should see when she mixes the two types of matter. •first, identify the physical state of matter of baking soda. describe another property of baking soda. •next, identify the physical state of matter of vinegar. describe another property of vinegar. •then, explain what janel should see when she mixes the baking soda and vinegar. •describe the states of matter of the new materials that are formed. •explain how janel can be certain a change has occurred. me

This drawing shows a human body system. what is the primary function of this body system?

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.