U would subtract 90 minus 45 which equals 45
Answer:
b. Add a few drops of one of the layers to a test tube containing 1 mL of water. Shake the test tube to determine the solubility of the layer in water
Explanation:
Option a is not true, it depends on the compound being extracted.
Option c is not true, although most of the solvents used in extractions have lower boiling point than water there are exceptions, for example toluene.
Option d is not true. Again most of the solvents used in extractions are less dense than water, there are many exceptions, for example chloroform, so for equal volumes the chloroform layer will weigh more.
Option b. is the correct one.
One will test the miscibility of the layer in water. If it inmiscible then one would know is the organic layer. If it is the aqueous layer then it will completely be miscible.
Answer:
If an atom gains or loses an electron, it bacomes an ion. An atom that gains a negative electron, it becomes a negative ion. If it loses an electron it becomes a positive ion
Explanation:
A lithium atom has 3 protons and 3 electrons. It can lose one of its electrons, making it an ion. It now has more positive protons than electrons so it has an overall positive charge. Therefore it is a positive ion.
A fluorine atom will tend to gain, rather than lose, an electron. By gaining a negative electron, it has an overall negative charge. It has become a negative ion.
