There are several differences between<span> a </span>physical and chemical change<span> in matter or substances. A </span>physical change<span> in a substance doesn't </span>change<span> what the substance is. In a </span>chemical change<span> where there is a </span>chemical<span> reaction, a new substance is formed and energy is either given off or absorbed.</span>
Answer:
Hydrogen bromide, anhydrous appears as a colorless gas with a pungent irritating odor. Corrosive. Heavier than air. Prolonged exposure to fire or intense heat may result in the violent rupture and rocketing of the container. Long-term exposure to low concentrations or short-term exposure to high concentrations can result in adverse health effects from inhalation. Used to make other chemicals and as a catalyst in the manufacture of chemicals. Rate of onset: Immediate Persistence: Minutes to hours Odor threshold: 2 ppm Source/use/other hazard: Chemical manufacturing industry; very corrosive.
Explanation:
HBr
Answer:
e. 327/227
Explanation:
This is the correct standard pressure.
The electron configuration that represent an excited state for an atom of calcium is 2, 8, 7, 3.
Calcium atom has an atomic number of 20 and its electronic configuration is 2, 8, 8, 2. An atom is said to be in an excited state if it gains energy and move to an higher energy level. For the calcium atom given above, there are 20 electrons which are distributed into four shells. But in the excited state [option 3], one of the 8 electrons in the third shell gains energy and move to the fourth shell. Thus, the number of electrons in the third shell reduced by 1, while the number of electrons in the fourth shell increase by 1.