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
The correct answer is From different social and ethnic backgrounds.
Explanation:
The purpose of science studies is to gain an understanding of specific phenomena and use this in the benefit of the world or humanity. Moreover, science is guided by objective methods and these are applied all around the world. This feature allows scientists from all kinds of social and ethnic backgrounds to study the same phenomena and obtain similar results, which is essential for the progress of scientific knowledge. This is exemplified by two different labs in two different countries studying drug absorption because the results of these two studies can be analyzed together to understand drug absorption.
In this context, one factor that contributes to the progress of scientific knowledge is the effort of scientists "from different social and ethnic backgrounds".
Answer:
A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does. In a chemical reaction, the atoms and molecules that interact with each other are called reactants. In a chemical reaction, the atoms and molecules produced by the reaction are called products.
Crush the limestone... it would give more area for the acid to react
Answer: Undecane, C11H24 is a liquid hydrocarbon from the alkane homologue ( family ).
Explanation:
All hydrocarbons burn in air to release H20 and CO2.
Combustion of hydrocarbons thus increases the percentage of CO2 present in the atmosphere which is not so good as CO2 is a greenhouse gas. Greenhouse gases produce the greenhouse effect. The green house effect is the warming effect produced when gases present in the atmosphere allow and retain the radiation from the sun to the earth. Examples of greenhouse gases are CO2, CH4, SO3, NO, CFCs. The greenhouse effect leads to an increase in the temperature of the earth subsequently leading to (I) melting of large amounts of ice at the poles causing flooding. (II) rapid evaporation of water from Earth’s surface. (III) decrease in crop yield.
Also, high concentration CFCs ( chlorofluorocarbons ), as widely used in aerosols, coolants and packaging foams, in the atmosphere depletes the ozone layer leading to global warming. In 1996 an international agreement was reached for a complete ban of CFCs and more countries are now going Green ( using alternative energy sources ) so as to minimize emissions of these greenhouse gases
