Answer : The magnetic moment of a single nickel atom is 
Explanation :
Formula used :

where,
= saturation magnetization = 
N = Avogadro's number = 
V = volume of nickel atom
= magnetic moment
First we have to calculate the volume of nickel atom.




Now we have to calculate the magnetic moment of a single nickel atom.



Therefore, the magnetic moment of a single nickel atom is 
Answer:
-1151.5 J
Explanation:
Given that:
The supplies energy = 245 L
The energy used in the expansion of gas = Pressure ×ΔV (change in volume)
At standard conditions;
Pressure = 105 × 10³ Pa
energy used in the expansion = 105 × 10³ Pa × (38.6 - 25.3)L
= 1396.5 J
Thus, the change in the energy of gas = 245 - 1396.5 J
= -1151.5 J
Hence, we can conclude that the gas has lost its own energy in the process of expansion.
I think the correct answer would be C. The common characteristic that is shareed by the elements found at the center of a period would be that they are the least reactive species. Having lower value of electronegativity, there is less ionization of the atoms which would also contribute to less reactivity.
Answer: The bond formed between magnesium and oxygen is an ionic bond.
Explanation:
An ionic bond is formed when an atom transfer its valence electrons to another atom.
Whereas, a covalent bond is formed by the sharing of electrons between the atoms.
Silicon and oxygen forms silicon dioxide. Silicon has 4 valence electrons which are shared with each oxygen atom. Hence, silicon and oxygen forms a covalent bond.
Oxygen and oxygen shares two pairs of electrons therefore, a covalent bond is formed between oxygen and oxygen.
A covalent bond is formed between carbon and hydrogen as carbon has 4 valence electrons which are shared with four hydrogen atoms.
Magnesium has 2 valence electrons which are transferred to the oxygen atom in order to complete its octet.
Therefore, the bond formed between magnesium and oxygen is an ionic bond.
Answer:
17. D. Chemical change
18. C. Cell wall
19. D. To transfer matter and energy within and between organisms.
20. A. Transporting materials
21. C. Carbon dioxide
22. A. Cellular respiration
23. C. Produce food and give off oxygen
Explanation:
I have been able to supply the correct answers. The cell wall functions as a structure that provides structural support and protection to the cell. It is tough, flexible and at times rigid. In a chemical change, new materials with new properties are manufactured. So, the process of photosynthesis is a chemical change.
The endoplasmic reticulum actually transports material. It transports materials like protein and lipids made within the cell and sends it to where they are needed.
Carbon dioxide is the the gas that animals give off and plants use it during photosynthesis. Cellular respiration involves the activities that result to the breaking down of food in order to release energy.