Astudent is investigating the affect of different salts on melting points. four patches of ice of equal size are roped off and a different type of salt is
poured on each, one receives table salt (nacl), one receives calcium chloride (cacl2), one receives potassium carbonate (kco3) and the fourth
receives inert sand instead. each patch receives an equal amount of salt or sand. the student measures the volume of ice remaining and subtracts
it from the original volume of ice to see how much melted away. what is the dependent variable?
• o a. the ice that received sand.
. b. the amount of ice that melted.
• c. the size of the ice patches.
• d. the type of salt applied to the ice.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called

1. the geologists have established a set of principals that can can be used o determine the relative ages of rock. this principal is applied to sedimentary and volcanic rocks. the rocks exposed to wall of grand canyon has layers and by studying the number of horizontal layers in the rock(strata) the relative age can be determined. the layer first formed will appear at the bottom and the the layer of strata last formed appear at the top. by using this information the approximate age of rocks can be determined.

2. carbon dating is used to find the relative age of rock in numbers which means for the rocks that has age between 1-70,000 years.

3. for the rocks of age range between 1,000 - billion of years potassium-argon dating is used.