your answer is Particles collide in gas so Substance X is a gas.
Answer:
Option C = Time
Explanation:
Speed:
''It is the distance travel in per unit time". It tells the capacity of moving object how fast it is moving. It is scalar quantity and can be explain just in term of magnitude. It does not require direction. For example we can say that someone is moving fast or moving slow. We are telling the magnitude of speed either its high or slow. If the object is not moving then its speed will be zero.
Formula:
r = d / t
r = speed (it can also be represented by v)
t = time taken to cover the distance
d = distance
Unit:
The system international unit of speed is m/s. It can also be given in Km/h
Example:
A car cover the 300 Km distance in a four hour. what is the speed of car?
Given data:
Distance = 300 km
Time = 4 hr
speed = ?
v = d / t
v = 300 km / 4 hr
v = 75 km/ hr
The speed of car is 75 km/hr.
Answer:
12.5g
Explanation:
1. Percentage of solution = 5.
2. Mass of solution = 250g.
3. = Mass of solute / 250 x 100.
4. = 5 x 250 / 100.
5. = 12.5g.
Answer:
group 16 period 2 of the periodic table
note: that is not the electronic configuration, that is the Bohr model.
Solution:
Carbon dating is only useful for relatively recent objects, it is more often used to date man-made. Fossils are dated using radiometric data from heavier elements like Uranium and by analysis of the strata in which they appear. Radiometric data is considered valid if several readings on the same object fall within a reasonable margin of error.
We use carbon dating because, Carbon dating only works on things that were once alive -- plant fossils, animal & human remains, etc.It works because when organisms are alive, they accumulate carbon during biological processes. Some of the carbon is carbon 14, a radioactive element whose ratio to normal carbon in living things is constant. When the organism dies, it stops accumulating carbon, and the carbon 14 decays radioactively with a half-life of about 5,700 years. It means 5,700 years after anything dies, there will be half as much carbon 14 as there was when it was alive. Measuring the ratio of carbon 14 to normal carbon in a fossil can give a pretty accurate measure of how long ago an organism died.