Inside your digestive system, protein molecules are broken down to amino acid molecules. (You can read about digestion on page 28.)
a Has a new substance been formed?
b Has a chemical reaction taken place​

може ли да зареждате повече информация, моля

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.

d : a person who learns about the world by observing it. no that is not a smiley face

explanation: