Answer:
He will use a radioactive element with a long half life of greater than 1 billion years
Explanation:
Rocks are an aggregation of solid mass which is usually rich in minerals. The age of rocks is established using radiometric dating method.
According to Oxford Dictionary, radiometric dating is "a method of dating geological specimens by determining the relative proportions of particular radioactive isotopes present in a sample."
The age of rocks can only be ascertained using isotopes that have very long half lives because many of these rocks are very old (aged billions of years) hence their age can only be determined using elements that has a half life greater than 1 billion years.
D: Where two continental plates are colliding, creating a convergent boundary. One plate slips under the other because of convection currents in the mantle.
Answer:
Acid base indicators are weak and acids and bases, which are used to signify the end point of neutralization reaction. The type of indicator used for a neutralization reaction depends on the strength of the acid and the base, that are involved in the reaction. A good acid base indicator must have a good pH range and it must be able to produce specific and identifiable color in specific acid base medium.
or
Two good properties of an indicator are as follows-
1) It should be specific- It means that the changes, which are measured by the indicator should be expressed in precise terms so that appropriate assessment could be made.
2) It should be time bound- This means that the measurable changes should arrive withing a particular time limit.
Example of indicator- Litmus is an acid base indicator that turns acidic solutions red and basic solutions into blue color.
Answer:
c) receptor; control center; effector.
Explanation:
Homeostasis maintains the internal body conditions almost constant. It includes specific cells that sense any deviations of internal or external conditions from the normal range. These cells are called receptors. The sensory information from the receptors is delivered to the control center. The central nervous system mainly serves as a control system wherein sensory information from the receptors is processed. The control center commands muscles and/or glands to perform desired responses to restore the homeostasis. Here, muscles and glands serve as effectors.
For example, thermoreceptors sense the rise of body temperature and the brain (control center) commands sweat glands (effectors) to produce sweat.
Answer:
5. pauk snelgrove states that oceans cobtribute significantly to not only sustaining life on earth but they are play a crucial part in nutrient
