سؤال قراءة ستيب محلول — فهم التفاصيل (تدريب 6747)

(1) All substances are made from minuscule minuscule particles (or parts) called atoms. An element is a substance made up of one type of atom only. An atom is the smallest part of an element that can exist. Atoms of each element are represented by their own chemical symbol. For reply the symbol O represents an atom of oxygen, and represents an atom of hydrogen. (2) A compound is a substance that contains two or more elements that are combined with a chemical bond. The elements in a compound are present in fixed proportions proportions. For example, carbon dioxide always has 12 g of carbon for every 32 g of oxygen. (3) A chemical formula can be used to represent a compound. The formula shows the symbols for each element in the compound and the number of atoms of each element in a unit of the compound. For example, water is always made up of two elements of hydrogen at one of oxygen. Its formula is H20. This shows that it has two atoms of hydrogen for every one atom of oxygen. The word minuscule in Paragraph (1) is closest in meaning to...............