A chemical reaction means molecules of one kind are changing to molecules of something different. For example, a chemical reaction occurs when we use an acid rust remover. This does not physically remove the rust. Rather it changes the rust to a new substance that is colorless.o use pH paper, moisten the stain slightly with water and press a piece of Phydrion paper to the carpet and check the color of the paper on the pH chart provided. Some of the color may transfer to the fibers. A safer way is to scoop up some of the moisture from the stain and apply this to the pH strip.
This is just the beginning. 1  The embryo is around 13 mm (1/2 inch) in length. 2  The heart is beating with one chamber. 3  A dividing wall is formed in the heart. 4  Arm and leg buds begin to grow. 5  The lower jaw and the vocal cords are beginning to form. 6  The mouth opening is formed. 7  The inner ear is being created. 8  The digestive tract is developing. 9  The ....
1 By the 22nd day, the heart starts to beat. 2  Your baby's neural tube begins to form. 3  This becomes the brain and spinal cord. 4  By the end of the first month, your baby is about 1/4 inch long.