29. B) A population changes in response to a change in the environment.
<u>Evolution is the process by which new species of organisms develop from earlier forms. Most often, in response to a change in a species environment. It's the frequent change of the alleles in a population. </u>
30. A) Describes the relationship between an organism and its environment
<u>Darwin made this theory of evolution by natural selection as an explanation for adaptation. Darwin defined natural selection as the </u>
<u>"principle by which each slight variation, if useful, is preserved."</u>
In each individual 3D water molecule models, the bonds between the hydrogen atoms and the oxygen atom are covalent bonds. ... Water molecules and ethanol molecules are polar covalent molecules while the ethane is a nonpolar covalent molecule. Ionic bonds are formed between the sodium and chloride ions.
1. Oxidation
2. Rapid Combustion
3. Respiration
4. Souring
5. Calcium
6. Photosynthesis
I hope this helps you out :D
Answer:
Explanation:
i. From solid to liquid (melting)
For melting to occur, heat must be absorbed by the substance being melted. When the substance gains significant amount of heat, its particles begins to vibrate and move on top of one another.
ii. From liquid to solid (freezing or hardening)
In this phase change, heat is removed from the system. This allows for the molecules to lose their kinetic energies and form an ordered arrangement from their liquid or molten state.
iii. From liquid to gas (evaporation)
As randomness continues to increase, more heat is absorbed to break the attractive forces between molecules of liquids. Phase change from liquid to gas is a heat absorbing process.
iv. From gas to liquid (condensation)
In condensation, heat is lost by a substance. To condense or collect gas particles together, heat must be removed from the system. This allows for a diminished kinetic energy among the particles of the system.
Barium Hydroxide is a strong base, so it completely dissociates into its ions when hydrated. The reaction would be
Ba(OH)₂ ⇒ Ba⁺² + 2 OH⁻
However, it would also follow the Law of Definite Proportions. So, the concentration of OH⁻ would be twice that of Ba(OH)₂, Therefore, the concentration of OH⁻ is 2(0.1 M) = 0.2 M OH⁻.
We use the concentration of OH⁻ to determine pOH. Then, we use the relationship between pOH and pH to determine the pH of the strong base. The equations are:
pOH = -log[OH⁻]
pH + pOH = 14
Therefore,
pOH = -log[0.2]
pOH = 0.6989
0.6989 + pH = 14
pH = 13.3