Answer:
alkali metals
Explanation:
they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.
The mass of iron (III) oxide (Fe2O3) : 85.12 g
<h3>Further explanation</h3>
Given
3.20x10²³ formula units
Required
The mass
Solution
1 mole = 6.02.10²³ particles
Can be formulated :
N = n x No
N = number of particles
n = mol
No = 6.02.10²³ = Avogadro's number
mol of Fe₂O₃ :

mass of Fe₂O₃ (MW=160 g/mol)

Answer:
Option D - 10,000 years ago in the Middle East
Answer : The correct answer is 74.83 m/s .
The kinetic energy is energy possessed by any mass which is moving or have some speed . It is product of mass and velocity . It is expressed as :

Where KE = kinetic energy in J or
m = mass in Kg v = speed in m/s²
Unit of KE is Joules (J) .
Givne : KE = 2100 J mass = 0.75 kg v = ?
Plugging value in KE formula =>


Dividing both side by 0.375 kg =>


