Answer:
n=1 holds two electrons and n=2 holds eight electrons.
Explanation:
Hello
In this case, since the atomic number of aluminum is 13, its electron configuration is:
In such a way, we can see that the level n=1 is filled with two electrons since the subshell s is able to hold two electrons and the level n=2 is also filled but with eight electrons as s holds two whereas p holds 6. Moreover, n=3 is holding three electrons.
Best regards.
The moving of molecules from areas of high concentration to that of low concentration to gain energy is best described as passive transport
<h3>What is passive transport?</h3>
Passive transport is a type of membrane transport in which chemicals are moved across cell membranes without using energy. Unlike active transport, which uses cellular energy, passive transport uses the second law of thermodynamics to cause the movement of substances across cell membranes.
<h3>Why is passive transport important?</h3>
Passive transport processes are critical to homeostasis. They maintain proper conditions inside the cell and the organism as a whole by letting chemicals to pass into and out of the cell.
To know more about Passive transport visit:
brainly.com/question/13542102
#SPJ4
Answer:
- <em><u>Mendeleev produced the first orderly arrangement of known elements.</u></em>
- <em><u>Mendeleev used patterns to predict undiscovered elements.</u></em>
Explanation:
- <u>Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.</u>
Those two statments are true.
For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.
More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).
The first modern chemistry book was written by Antoine Lavoisier (this discards first option).
Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).
Isotopes were not known by Mendeleev times, so this discards the last option.
The process by which rocks are broken down to form soil is called weathering. It is divided into 3 types, physical, chemical and biological weathering.
Physical weathering is the process by which rocks are broken down as a result of physical agitations. It is also called mechanical weathering and during this process the chemical nature of the rock is not affected. Biological weathering has to do with the weakening of rocks and their eventual disintegration as a result of plants and animals activities. Chemical weathering refers to the disintegration of the rock particles as a result of chemical reactions.
Answer:
Strong acid
Explanation:
An acid is a substance that interacts with water to produce excess hydroxonium ions in an aqueous solution.
Hydroxonium ions are formed as a result of the chemical bonding between the oxygen of water molecules and the protons released by the acid due to its ionisation. This makes aqueous solution of acids conduct electricity.
A strong acid is one that ionizes almost completely. Examples are:
1. Hydrochloric acid
2. Tetraoxosulphate (VI) acid
3. Trioxonitrate (V) acid
4. Hydroiodic acid
5. Hydrobromic acid
