Answer:

Definition:
Half-life- The time taken for half of the radioactive isotopes to decay.
Explanation:
How does radioactive decay work? Radioactive decay is a process by which unstable nuclei become more stable through the emission of alpha or beta particles or gamma rays.
Since a half-life is the time taken for half of the isotopes to decay, we can simply divide the initial mass of 100 grams by 2; this gives us 50 grams.
1) Divide 100g by 2.

Answer:
So the answer would be water based on the evidence shown below.
Explanation:
Mercury is a poor conductor of heat but good for electricity, water is a good conductor of heat but a poor conductor of electricity, wood is a poor conductor of heat and electricity, and glass is probably the worst conductor of heat.
It is called observation because you observe with your nose by semlling things your eyes by looking at things your ears by hearing things your tongue by tasting things and your hands by feeling things
Answer:
a) If we apply pressure to a fluid in a sealed container, the pressure will be felt undiminished at every point in the fluid and on the walls of the container.
Explanation:
Pascal´s Principle can be applied in the hydraulic press:
If we apply a small force (F1) on a small area piston A1, then, a pressure (P) is generated that is transmitted equally to all the particles of the liquid until it reaches a larger area piston and therefore a force (F2) can be exerted that is proportional to the area(A2) of the piston.
P=F/A
P1=P2
F1/ A1= F2/ A2
F2= F1* A2/ A1
The pressure acting on one side is transmitted to all the molecules of the liquid because the liquid is incompressible.
In an incompressible liquid, the volume and amount of mass does not vary when pressure is applied.
The body will take 20 seconds to cover a distance of 1000 m i.e. 1 km