<u>Answer:</u> The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g
<u>Explanation:</u>
We are given a function that calculates the amount of sample remaining after 't' years, which is:

Putting values in above equation:


Hence, the amount of sample left after 20 years is 288.522 g
Putting values in above equation:


Hence, the amount of sample left after 50 years is 144.26 g
THE DISTANCE IN TM SHOULD BE EQUAL TO 162 KM
Answer:
17 protons, 20 neutrons, and 17 electrons.
Explanation:
A periodic table can be defined as the standard arrangement of chemical elements by atomic number, electronic configuration and chemical properties in a tabular form.
Generally, a proper representation of the mass number and atomic number of chemical elements is key and very important in chemistry.
Furthermore, as a rule, it should be noted that the mass number (nucleon number) is always larger than the atomic number(number of proton).
The mass number of this neutral atom of Cl-37 is 37 and we know that the atomic number (number of protons) of chlorine is 17. Also, the atomic number of an element is equal to the number of its electrons.
A neutral atom of Cl-37 has 17 protons, 20 neutrons, and 17 electrons.
Hence, a neutral atom of Cl-37 can be identified based on its number of protons because it represent its atomic number, which is what is used to differentiate an atom of an element from the atom of another chemical element.
Element on the right side of the periodic table differ from the elements on the left side in that elements on the <em>right side are non metallic and tends to be gases at room temperature.</em>
<em> </em><u>Explanation</u>
In the periodic table there element in the right side , left side and those which are in between.
- Example of element in the right side is fluorine chlorine, neon, Argon among others.
- This element have higher effective nuclear charges and stabilize electrons more effectively.
- there electrostatic intermolecular forces are generally weak therefore they exist in liquid or gaseous state.