Answer:
D - chemical and physical
Explanation:
Only chemical and physical changes can reach the level of dynamic equilibrium. Nuclear reactions cannot reach dynamic equilibrium.
- A system is in dynamic equilibrium when the rate of forward reaction is the same as that of backward reaction in a reversible reaction.
- Nuclear reactions cannot be reversed.
- Dynamic equilibrium is prominent in chemical reactions. It is commonly found that as a reaction occurs, the backward and forward reactions can reach equilibrium levels.
- In physical changes, this can also occur when certain conditions of pressure and temperatures are satisfied.
Answer:
126.5g
Explanation:
n=<u>m</u><u> </u>
M
where n is moles
m is mass of substance
M is molar mass
molar mass of sodium is 23g/mol
m=nM
m=5.5(23)
m=126.5
Answer:
Explanation:
Group one:
The elements of group one shows +1 charge because these all are metals and lose their one valance electron.
Hydrogen lithium sodium potassium rubidium cesium francium
Group 2:
The elements of group two shows +2 charge because these all alkali metals and lose their two valance electrons.
beryllium magnesium calcium strontium barium radium
Group 3:
The elements of group three-B shoes +3 charge by losing three valance electrons.
Scandium yttrium lanthanum actinium
Group 4:
The elements of group 4th A and 4th B lose four electrons or gain four electrons to complete the octet and shows +4 or -4 charge.
Group 5:
Group 5th elements gain three electrons and shows -3 charge to complete the 8 electrons. (octet).
It involve the elements of group 5th A.
Group 6:
The elements of group 6A gain two electrons to complete the octet and shows -2 charge.
Group 7:
The elements of group 7A gain one electron to complete the octet and shows -1 charge.
Group 8:
The elements of group 8A are noble gases and have complete octet. That's why shows 0 charge.
J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model. In Thomson's model, the atom is composed of electrons (which Thomson still called “corpuscles,” though G. J.
