After first half-life you will have 100/2=50g. After second half-life you will have 50/2=25g.
The theory that describes the motion and force driving earth's plates is Plate tectonics
Explanation:
Plate tectonics states that the outer shell of the Earth is divided into plates that glide and move over the mantle which is the surface of the earth.
The mantle is the rocky inner layer above the core of the Earth.
Plate tectonics helped the geologists to explain how continents could move around the planet.
There are 9 major plate tectonics , namely North American, Pacific, Eurasian, Australian, African, Indo - Australian,Indian South American and Antarctic. These plates have been named after the land form found on them.
Answer:
is the density of solid calcium.
Explanation:
Formula used :
where,
= density
Z = number of atom in unit cell
M = atomic mass
= Avogadro's number
a = edge length of unit cell
We have:
r = 197 pm = 
M = 40 g/mol
Z = 4
On substituting all the given values , we will get the value of 'a'.
is the density of solid calcium.
The properties of matter can best be explained using a model in which all materials are composed of tiny particles (atoms, molecules and ions). There is empty space between particles and particles are constantly moving (their speed is changed by temperature).
