B) the bacteria that live in the intestine of a rabbit
Answer:
A. Has only one kind of atom
Explanation:
All forms of matter are composed of elements.
An element is a substance which cannot be broken down into simpler units or converted into other substances by ordinary chemical reactions. Each element is composed of only one kind of atoms which are unique to each element. There are three fundamental sub-particles present in atoms of elements; these are: protons, electrons and neutrons. An atom of an element differs from an atom of another element by its atomic number. The atomic number of an element is the number of protons present in the nucleus of the atom of that element. For example, hydrogen atoms has an atomic number of 1, while sodium atoms has an atomic umber of 11.
Atoms of the same element or different elements may combine together to form the molecules of a substance. For example, a molecule of hydrogen gas is made up of two atoms of hydrogen whereas a molecule of water is composed of two atoms of hydrogen and an atom of oxygen.
Elements can exist in any of the three physical states: solids, liquids or gases. For example, hydrogen exists as gas, mercury as a liquid, while gold exists as a solid.
The elements heavier than hydrogen and helium were produced inside stars.
During most of a star's lifetime, hydrogen nuclei fuse together to form helium nuclei.As the star runs out of hydrogen, other elements. Heavier elements than hydrogen and helium are form. Elements heavier than iron are formed in supernovas.
Answer:
The correct answer is - hard water reacts to form the calcium or magnesium salt of the organic acid of the soap.
Explanation:
Soaps are made up of fatty acids or oils by treating with strong alkali and are salts of sodium and potassium. Hard water, on the other hand, has a high concentration of minerals in comparison to soft water. When hard water and soap are mixed together the salts of the minerals like Ca2+ and Mg2+ ions present in hard water react with fatty acids of the soap.
The sodium salts are changed to the salts of calcium and magnesium which are precipitated to an insoluble substance. The insoluble salts of the calcium or magnesium dirt stick on the clothes thus cleaning ability of soap is reduced.