Answer:
a. absorbs energy as heat and has positive enthalpy of solution.
Explanation:
A reaction can either be exothermic or endothermic. An endothermic reaction, as the dissolution described in the question, is that which absorbs heat energy from the surroundings in order to start the reaction.
Because an endothermic reaction makes heat lost from the surroundings, the enthalpy (∆H) of the solution will be positive (+). ∆H is got by finding the difference between the enthalpy of the reactants and products and since the enthalpy of a product in endothermic reaction is more, the enthalpy change (∆T) will be positive.
Answer:
A. Peroxide breaking down into water and oxygen
Explanation:
Generally when it comes to changes, there are physical and chemical changes. In physical changes, there are no new substances been formed, however in chemical change new substances are formed.
A. Peroxide breaking down into water and oxygen
This is a chemical change.
B
. Bubbles forming when a pot of water is heated
This is a physical change
C. A pair of jeans soaked in water drying after hanging outside
This is a physical change
D
. A block of ice decreasing in size due to a change in temperature
This is a physical change.
Only option A is different from the rest,hence this is the answer.
Answer:
B) diffraction
Explanation:
A smooth pane of glass does not diffract light. A light passing through a smooth pane of glass may be absorbed, reflected or transmitted.
Diffraction only occurs with special types of glasses embedded with a diffraction grating and are called super prisms. Diffraction glasses use a a gradient lens which is able to separate light into all the colors of the rainbow.
Recall that diffraction is the separation of white light into its component wavelengths.
It is called a dactyloscopy
Answer:
Its reliability is confirmed by many scientists
Explanation:
The science and the pseudoscience have multiple differences that separate them clearly and sharply. The science, doesn't matter about scientific field we are talking about, is confirmed by numerous scientists. In order for something to be accepted in the scientific circles as a science, the particular thing in question undergoes numerous studies, from numerous different scientists or scientific groups. If all of the results of all of the studies are confirming the same thing, that it can be accepted as science.
