A is the answer. Chemical changes happen when atomic bonds are broken or created during chemical reactions. Hence, in this case, it involve changes to molecular structure.
- Change in states are physical changes.
- When salts are dissolved in water, you can use Distillation to separate them. Distillation is a physical change as well.
- Dissolving is just physical change.
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
Answer:
Horizontal lines that represent different climate zones are called latitude.
Explanation:
Latitude is the distance that exists between a point on the Earth's surface to the equator, counted by the degrees of its meridian. That is, it is the distance, measured in degrees, that exists between any parallel and the line of the Equator. The latitude of a point is measured to the North or South of the zero parallel and its value can vary between 0 ° from the equator to 90 ° N from the North pole or 90 ° from the South pole.
Climate is related to latitude because it sets the amount of solar energy that a given region or place receives. Places located at high latitudes (far from the Ecuador) receive less sunlight than places located at low latitudes (near the Equator). Thus, cities distant from the equator and close to the poles have a cold climate, while at low altitudes there are high temperatures and a hot or tropical climate.
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
Answer:Accounting for the sizes of protons, neutrons, and electrons, most of the volume of an atom—greater than 99 percent—is, in fact, empty space. ... The electrons that surround all atoms are negatively charged and cause atoms to repel one another, preventing atoms from occupying the same space.
Explanation: hope this helped
