Two key characteristics of a good scientific investigation are hypothesis and observation of whatever organism your studying.
Answer:
The correct answer is - d) all choices are correct.
Explanation:
Cattles remember the behaviour of human how they have treated them in the experiment and they also become less fearful of their handlers due to their gentle treatment.
Cattles develop memory and have a bond with their handlers and remember them and recognize them very well. In this experiment, it is found that animals also create an emotional bond with the human treat them well and gentle.
Hazardous substances are dangerous substances while toxins are poisonous substances. Hazardous substances may cause harm to an individuals health; they include acute toxins such as cyanide; substances harmful after repeated or prolonged exposure such as mercury and silica, among others. Toxic substances can be poisonous or cause health effects.
Answer:
A. test the composite drug in a trial run
Explanation:
The statements which are true about half-life are given below:
- A radioactive element's half-life stays the same when its temperature changes.
- A radioactive element's half-life stays the same when the pressure upon it changes.
Thus, the correct options are B and F.
<h3>What is Half-life?</h3>
The half-life of any radioactive element may be defined as the time taken for the radioactivity of a specified isotope to drop to half of its original value.
The above statement is true about the half-life of any radioactive element because the half-life of any substance does not depend on pressure, temperature, and concentration.
Therefore, it is well described above.
To learn more about Half-life, refer to the link:
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