Answer:
C
Explanation:
A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.
A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.
Answer:
<em>Gases tend to deviate from ideal gas law at </em><u><em>high pressures and low temperatures.</em></u>
Explanation:
The main statements from molecular kinetic theory to describe an ideal gas is that 1) the gas particles occupy a neglictible fraction of the total volume of the gas, and 2) there is not force of attraction between gas particles.
HIgh pressure means that the gas particles will be forced closer to each other, making that the mean distance between the particles be realtively more important and their volume less neglictible. This is a violation the first assumption described above.
Since the temperature is directly related to the kinetic energy, and the latter with the movement of the particles (average speed), low temperatures lead to the molecules being less independent of each other, i.e. the forces between the molecules will count more . This fact constitutes a violation of the second principle established in the first paragraph.
In <u>conclusion</u>, <em>high pressures and low temperatures tend to deviate gases from the ideal gas law.</em>
You can read more about ideal and real gases behavior on brainly.com/question/12449772
A model of the atom devised by Ernest Rutherford.
Answer: Option (5) is the correct answer.
Explanation:
It is known that the ground state electronic configuration of silicon is ![[Ne]3s^{2}3p^{2}](https://tex.z-dn.net/?f=%5BNe%5D3s%5E%7B2%7D3p%5E%7B2%7D)
.
And, we know that when an atom tends to gain an electron then it acquires a negative charge and when an atom tends to lose an electron then it acquires a positive charge.
As 
has a +4 charge which means that it has lost 4 electrons. Hence, the electronic configuration of is 
.
According to the Aufbau principle, in the ground state of an atom or ion the electrons fill atomic orbitals of the lowest energy levels first, before filling the higher energy levels.
As 2p orbital is filled after the filling of 2s orbital.
Therefore, we can conclude that 2p orbital will be occupied by the electrons of highest energy for the ground-state ion.
Answer:
c. Histidine
Explanation:
Histidine is a compound that is normally used for the generation of protein. Three amino acids commonly have basic side chain when the pH is neutral. The conjugate acid in histidine has a pKa of approximately 6. Based on the description of the experimental analysis provided in the statement, the right option is option c.
