b. A piece of silver flatware tarnishing
c. Dry ice subliming into carbon dioxide
d. Two clear solutions forming a precipitate when mixed
B. Pandemic
C. Epidemiology
D. Toxicology
The answer is A
The bacteria that cause disease are known as pathogens. The term pathogen is used to refer to all types of disease causing microorganisms. These include bacteria, fungi, protozoa and fungi.
Bacteria. Microscopic organisms that come in many shapes and sizes. Some bacteria that cause disease in man are Salmonella typhi which causes typhoid and Streptococcus pyogens which causes sore throat.
Virus. A virus is a microscopic entity much smaller than even bacteria and can only exist inside a host such as a cell. It cannot live on its own. Some viruses that cause disease are HIV which causes AIDS and Rhino virus which causes colds.
Fungi. These are a group of unicellular or multicellular microscopic organisms that live by feeding on organic matter. A type of fungus that causes disease is Trichophyton mentagrophyte which is responsible for athlete's foot.
Protozoa. A group of one celled organisms which live in water. Entamoeba histolytica is a protozoa, an amoeba which causes amoebic dysentery in man.
B. The neutrons do not affect the mass or stability of an atom's nucleus, but they are involved in most interactions between two atoms.
C. The neutrons do not affect how the atom interacts with other atoms, but they do have an effect on the mass and stability of the nucleus.
Answer:
See explanation for details
Explanation:
ammonium sulfate and barium nitrate Answer
Ba2+(aq) + SO4^2-(aq) ----------> BaSO4(s)
lead(II) nitrate and sodium chloride Answer
Pb2+(aq) + 2Cl-(aq) -----------> PbCl2(s)
copper(II) chloride and sodium hydroxide Answer
Cu2+(aq) + 2OH-(aq) -------------> Cu(OH)2(s)
There can only be a net ionic reaction when a precipitate is formed as the two solutions are mixed together.
There are no net ionic equations for the given reactions as neither of them forms a precipitate.The correct option is no reaction.
The reactions are as follows:
Ionic equation is defined as a chemical equation which represents electrolytes in aqueous solutions and are expressed as dissociated ions. Ions present in aqueous solutions are stabilized by ion dipole interactions with the water molecules which are present.
An ionic equation can be written for any electrolyte which dissociates and reacts with the polar solvent. In a balanced ionic equation , number and type of atoms on each sides of reaction arrow are same. Even the net charge on both sides of the arrow is same.
There can only be a net ionic reaction when a precipitate is formed as the two solutions are mixed together.Thus, the correct option is no reaction.
Learn more about ionic equation,here:
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