Answer: Option A) 25mL
Explanation:
Given that,
Original volume of gas (V1) = 75mL
Original temperature of gas (T1) = 450K
New volume V2 = ?
New temperature T2 = 150K
Since volume and temperature are given while pressure is held constant, apply the formula for Charle's law
V1/T1 = V2/T2
75mL/450K = V2/150K
To get the value of T2, cross multiply
75mL x 150K = 450K x V2
11250mL•K = 450K•V2
Divide both sides by 450K
11250mL•K / 450K = 450K•V2/450K
25mL = V2
Thus, the new volume of the gas is 25mL
Chromium phosphate pentahydrate
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
Answer:
Burning of the candle is both physical and chemical change. Burning of the candle melts the wax and hence physical state of wax has changed from solid to liquid.
Again the wax combines with the atmospheric oxygen and changes to carbon dioxide, heat and light.
Thus both the changes are accompanied by the burning of the candle.
Explanation:
hope this helps!
~mina
The answer would be the third one listed, Refraction
