Question 17
metal ions in water can react with soap to form
a)acid-base indicators
b)detergents
c)salts
d)soap

Metal ions in water can react with soap to form salts. ( option C)

Explanation:

Soaps have the general formula (RCO2−)nMn+ (Where R is an alkyl, M is a metal and n is the charge of the cation).

C17H35COO- Na+

The class of soaps is determined by the identity of Mn+. Those can be mettalic or lithium soaps.

Let's consider those metals are calcium or magnesium ions, dissolved, with soap, in the water, we'll find that the sodium ion (Na+)  at the polar end of the soap molecule is replaced by a metal ion such as calcium or magnesium ion. This will result in a salt, ( better said an insoluble fatty acid) salt.

This can be shown with the following reaction:

2 C17H35COO- Na+ + Ca2+  → (C17H35COO)2Ca + 2Na+

This results in Calcium stearate, which is the calciumcarboxylate  (calcium salt) of stearic acid.

Metal ions in water can react with soap to form salts.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.

c. establishing proper sleep hygiene