Answer:
It is a chemical change.
Explanation:
When the electricity is off, the filament cools down to its original physical state. This physical process repeats every time the light is turned on and off. However, if the bulb is cracked and air is introduced, the oxygen in the air reacts with the tungsten filament which then undergoes a chemical change.
Answer:
C. The half-life of C-14 is about 40,000 years.
Explanation:
The only false statement from the options is that the half-life of C-14 is 40,000yrs.
The half-life of an isotope is the time it takes for half of a radioactive material to decay to half of its original amount. C-14 has an half-life of 5730yrs. This implies that during every 5730yrs, C-14 will reduce to half of its initial amount.
- All living organisms contain both stable C-12 and the unstable isotope of C-14
- The lower the C-14 compared to the C-12 ratio in an organism, the older it is.
Answer:
Detail is given below.
Explanation:
Similarities:
All are the forms of matter.
Solid, liquid and gases are made up of ions, atoms and molecules.
They have shape and volume.
Molecules in Liquid and solid are closer to each others.
Liquid and gases can flow very easily.
Liquid and solid both can not compressed very easily.
Differences:
Molecule of gases randomly move everywhere and occupy all available space but liquid and solid's molecules are not move as much easier as molecules of gases can.
The density of gases are very low as compared to the liquid and solid.
Gas molecules are at long distance from each other while in liquid and solid they are closer to each other.
The very weak inter molecular forces are present between gas molecules as compared to the liquid and solids.
Solids have definite volume and shape but liquid and gases acquire the shape of container.
In solids molecules are tightly pack and very close to each other while in liquid molecules are not tightly pack like in case of solid.
The densities of solids are also very high as compared to the liquid and gas.
There are very strong inter molecular forces are present between solid molecules.
One system must have higher kinetic energy than the other system
