The building blocks of the universe are called

1)ions
2)elements
3)compounds
4)nuclei

"Nuclei " are called as building blocks of the universe.

Option: D

Explanation:

Smallest unit of this universe was considered to be an atom but “Rutherford 's Nuclear Model of Atom” in 1911 discovered nucleus which is small and heavy positively charged body present in center of atom. An atom also have extra nuclear part which is space around nucleus, where electrons (negative charged) are distributed. Nucleus is contained with protons (positive charged) and neutrons (neutral) which are definitely very smaller than nuclei but as a building unit or block of the universe nuclei is considered.  

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i  

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.