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## What does the number in front of the formula represent?

The number in front of a chemical formula in a reaction equation is called **the coefficient**. It’s there to balance the equation.

## What do the symbols and numbers mean in the formulas?

The letters in a chemical formula are **the symbols for the specific elements**. … You can now interpret chemical formulas. For example, many people know H_{2}O is water, but now you know that the H means hydrogen and the O means oxygen, and the number 2 after the H means that there are two hydrogen atoms for every oxygen atom.

## What does the 2 in front of 2H2O mean?

A coefficient multiplies the number of atoms of each element indicated in a chemical formula. Thus, 2H2O represents **four H atoms and two O atoms**. … side to four by placing the coefficient 2 in front of the molecular formula for oxygen.

## What does the 2 in front of the NaCl mean?

If we start out with two chlorine atoms in the reactants, we must end up with two chlorine atoms in the products. … In the above example we added a two in front of the Na and NaCl symbols to indicate **2 sodium atoms react with 1 chlorine molecule to give 2 sodium chloride molecules**.

## What are the small numbers in front of some formulas called?

The numbers placed in front of formulas to balance equations are called **coefficients**, and they multiply all the atoms in a formula. Thus, the symbol “2 NaHCO3” indicates two units of sodium bicarbonate, which contain 2 Na atoms, 2 H atoms, 2 C atoms, and 6 O atoms (2 X 3= 6, the coefficient times the subscript for O).

## What does a formula of compound represent?

A chemical formula is an expression that **shows the elements in a compound and the relative proportions of those elements**. … Molecular formulas do not indicate how the atoms are arranged in the molecule. The empirical formula tells the lowest whole-number ratio of elements in a compound.

## What is the bottom number on an element?

The number below the symbol is **the atomic number** and this reflects the number of protons in the nucleus of each element’s atom. Every element has a unique atomic number. Lead has 82 protons therefore its atomic number is 82.

## How can you tell if an empirical formula is correct?

Chemical formulas tell you how many atoms of each element are in a compound, and empirical formulas tell **you the simplest or most reduced ratio of elements in a compound**. If a compound’s chemical formula cannot be reduced any more, then the empirical formula is the same as the chemical formula.

## What is the O in H2O?

O is the chemical formula for water, meaning that each of its molecules contains **one oxygen and two hydrogen atoms**. H.

## What is H2O full name?

H_{2}O is the molecular formula of water, also called **Dihydrogen monoxide**. H_{2}O symbolises two hydrogen atoms and one oxygen atom.