40o+2 protons electrons And neurons

There are few simple rules to follow.

(1) The atomic number is equal to the number of protons.

Z

= number of protons

(2) In neutrally charged elements, the number of electrons is the same as the number of protons.  

Z

= number of protons = number of electrons (no charge)

Otherwise, positive charge means that the element lost an electron and negative charge means it gained an electron.

(3) The atomic mass is equal to the sum of the number of protons and number of neutrons.

A

= number of protons + number neutrons  

or

A

=  

Z

+ number neutrons

So if you say that  

Z

= 20 and  

A

= 40, then

A

=  

Z

+ number neutrons

40 = 20 + number of neutrons

40 - 20 = number of neutrons

Therefore,

number of neutrons = 20

Explanation:

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

answersilicon (si); oxygen (o);