Answer:
Periods have consecutive atomic number as they are in a row and groups are vertical meaning they are in a column and groups have similar properties
The correct answer among the choices given is option A. Eustachian, Pharynx, Bronchi are structures that ensembles a tube. The Eustachian tube is a narrow passage from the pharynx to the middle ear. Pharynx is a passageway leading from the oral and nasal cavities to the larynx and the esophagus. Lastly, bronchi is an airway in the respiratory tract.
<span>If thermal energy (heat) must be added to a chemical reaction in order for the reaction to take place, the reaction is endothermic. </span>
Answer:
NH₃ (Option A)
Explanation:
Arrhenius theory explained that the acids are the ones that have H⁺, either H in its formula. Following this, the bases are the ones that have OH⁻ , either OH and its formula.
It can be used only with compounds with H, or OH.
So the ammonia is not a base, as Arrhenius theory.
It is known that ammonia behaves as a weak base, but it does not have hydroxide ions that can yield to water
Answer: No
Explanation: <em>Reactants</em> are the substances present at the beginning of a chemical reaction. In the burning of natural gas, for example, methane (CH4) and oxygen (O2) are the reactants in the chemical reaction. <em>Products </em>are the substances formed by a chemical reaction. In the burning of natural gas, carbon dioxide (CO2) and water (H2O) are the products formed by the reaction.
