2021년 3월 모의_[ 고1 ]_37번

Anne숑 · [ 고1 ] [ 2021 3월 ] 37번

❶    If you had to write a math equation, you probably wouldn’t write, “Twenty-­eight plus fourteen equals forty-­two.”

 

❷   It would take too long to write and it would be hard to read quickly.

      You would write, “28+14=42.”

                                 

 

 

❸  Chemistry is the same way.

 

❹   Chemists have to write chemical equations all the time, and it would take too long to write and read if they had to spell everything out.

 

❺   So chemists use symbols, just like we do in math.

 

❻  A chemical formula lists all the elements that form each molecule and uses a small number to the bottom right of an element’s symbol to stand for the number of atoms of that element.  

 

 

 

 

❼  For example, the chemical formula for water is H2O.

 

❽  That tells us that a water molecule is made up of two hydrogen (“H” and “2”) atoms and one oxygen (“O”) atom.