<u>Answer:</u>
<em>B. A and B</em>
<em></em>
<u>Explanation:</u>
1. Solids have a definite volume, definite size and definite shape
2. The particles present in a solid are very closely packed since the intermolecular forces between them are very strong. The molecules do not move apart.
3. Melting point is the temperature at which solid changes into a liquid.
4. When a solid is heated to the melting point the intermolecular forces are overcome by the energy and the molecules present in it moves from its fixed position to take its liquid state which is called as melting.
<span>B. 51 50
Z and Z
25 25
It is because only this element have equal number of Protons (Bottom number) and are different in atomic masses (upper number)
Hope this helps!</span>
Answer:
[CO2] > [N2] > [He]
Explanation:
The relative concentration of CO2, N2 and He depends on the solubility of each gas in water. The more soluble in water a gas is, the greater its concentration in aqueous solution.
Among the gases listed, CO2 is most soluble in water hence it is expected to have the greatest concentration in solution followed by N2. Helium gas is insoluble in water hence it has the least concentration in the aqueous solution.
Answer:
Solute = 5 mL; solution = 250 mL
Explanation:
The formula for percent by volume is

If you have 250 mL of a solution that is 2 % v/v,

If there is no change of volume on mixing,
Volume of solution = 250 mL
-Volume of solute = <u> </u><u>5</u><u> </u>
Volume of solvent = 245 mL
<span>Get a periodic table of elements. ...Find your element on the periodic table. ...Locate the element's atomic number. ...Determine the number of electrons. ...Look for the atomic mass of the element. ...<span>Subtract the atomic number from the atomic mass.</span></span>