Chemical Reaction

When materials combine to form new compounds it is a chemical change. Which example is a chemical change?( baking powder fizzing-water boiling-ice melting-sugar cube dissolving)

The reactants in the image above are:(CH4 and 2 O2----2 H2O and CO2)

How many hydrogen atoms are in this chemical formula CH4 : (4-1-2-3) Hydrogen atoms

Is burning wood a chemical or physical change?

Which example provides evidence of a chemical change? 1-Wood releases ash and smoke when burned.-2-Boiling water bubbles when being heated.-3-Rock particles separate when soil is being sifted.

A group of atoms bonded together. (A Molecule --- The Coefficient--- The Subscript---- An Atom Party)

What is a chemical reaction? 1-a change in matter when the molecules rearrange to make new molecules //2-a change in matter when matter changes its form or appearance

Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?

This change is a --------------- ( physical change- Chemical change )

Is glass breaking a chemical or phyiscal change?