Use your periodic table of elements. take any element of your choosing (from period 4 or above) and answer the following questions: what is the element's name and symbol? is it a metal, nonmetal, or metalloid? which family does it belong to? how many protons, neutrons, and electrons does its neutral atom have?

Solution: We are taking second element from the 4th period.

Element's name is Calcium.

It's symbol is Ca.

It is a metal because it looses its valence electron to form positive ions.

Calcium element lies in the second group of 4th period. The elements belonging to the second group are known as alkaline earth metals.

Atomic Number of Calcium = 20

Atomic number = Number of protons = Number of electrons

therefore,

Number of electrons and protons = 20

Atomic Mass of Calcium = 40

Atomic Mass = Number of neutrons + Number of proton

bu substituting the values of atomic mass and number of prtons, neutrons can be calculated

Number of neutrons = 20.

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied