Answer:
a frisbee flaying in the air
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where;
- K.E represents kinetic energy measured in Joules.
- M represents mass measured in kilograms.
- V represents velocity measured in metres per seconds square.
Hence, an example of kinetic energy at work is a frisbee flaying in the air because it would possess energy due to its motion in the air.
The phase of a substance at a temperature of 275 K or 1.85 degrees Celsius can be any of the three phases namely a solid, a liquid and a gas. This depends on the pressure where the substance is subjected. Also, the phase can be determined by a phase diagram where it shows the phase of a certain substance at a specific temperature and pressure.
Answer:
-250.3kJ
Explanation:
Based in the reactions and using -<em>Hess's law-</em>:
(1) P₄(s) + 6 Cl₂(g) → 4PCl₃(g) ΔH₁ = -4439kJ
(2) 4PCl₅(g) → P₄(s) + 10Cl₂ ΔH₂ = 3438kJ
The sum of (1) + (2) is:
4PCl₅(g) → 4PCl₃(g) + 4 Cl₂ ΔH = -4439kJ + 3438kJ = -1001kJ
Dividing this reaction in 4:
PCl₅(g) → PCl₃(g) + Cl₂ ΔH = -1001kJ / 4 = <em>-250.3kJ</em>
Answer:
1.25 gram of cesium-137 will remain.
Explanation:
Given data:
Half life of cesium-137 = 30 year
Mass of cesium-137 = 5.0 g
Mass remain after 60 years = ?
Solution:
Number of half lives passed = Time elapsed / half life
Number of half lives passed = 60 year / 30 year
Number of half lives passed = 2
At time zero = 5.0 g
At first half life = 5.0 g/2 = 2.5 g
At 2nd half life = 2.5 g/ 2 = 1.25 g
Thus. 1.25 gram of cesium-137 will remain.
Answer : The correct option is, (C) 10-mL volumeric pipet.
Explanation :
Graduated cylinder : It is a measuring cylinder that is used to measure the volume of a liquid. It has a narrow cylindrical shape. The marked line drawn on the graduated cylinder shows the amount of liquid that has been measured.
Pipet : It is a type of laboratory equipment that is used to measure the volume of a liquid. It is small glass tube and the marked line drawn on the pipet. It is used to accurately measure and transfer of volume of liquid from one container to another.
Volumetric flask : It is a type of laboratory tool that is also used for measuring the volume of liquid. It is used to make up a solution to a known volume. It measure volumes much more precisely than beakers.
Beaker : It is a type of laboratory equipment that has cylindrical shape and it is used for the mixing, stirring, and heating of chemicals.
As per question, we conclude that the pipet is most precise than other devices because in pipet the marking lines are more accurate. Thus, it can be used to measure volume to precision.
Hence, the correct option is, (C) 10-mL volumeric pipet.
