Which of the following best explains why the alkali metals have similar chemical properties? Choose 1
They are in the same period of the periodic table and so have the same number of valence
electrons.
B
They are in the same period of the periodic table and so have the same atomic number.
They are in the same group of the periodic table and so have the same number of valence electrons.
They are in the same group of the periodic table and so have the same atomic nu

i wish i could but this one is weird give me abc and i can solve it.

(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