Rare earth metals are a group of 17 elements - lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground
Air bubbles, i just had this question on a test.
The correct answer would be D. Ca^2+ has 18 electrons. This is because 2+ means that 2 electrons have been removed, and Ca starts out with 20 electrons. As 20 - 2 = 18 electrons, D is the correct answer.
Hope this helps!
Explanation:
Expression for the 
speed is as follows.
where, = root mean square speed
k = Boltzmann constant
T = temperature
M = molecular mass
As the molecular weight of oxygen is 0.031 kg/mol and R = 8.314 J/mol K. Hence, we will calculate the value of as follows.
= 
= 498.5 m/s
Hence, for oxygen atom is 498.5 m/s.
For nitrogen atom, the molecular weight is 0.028 kg/mol. Hence, we will calculate its speed as follows.
= 
= 524.5 m/s
Therefore, speed for nitrogen is 524.5 m/s.
Answer:
The correct option is;
a. The particles will gain a large amount of kinetic energy
Explanation:
As the water temperature reaches 100°C, which is the boiling point for water at atmospheric pressure, the continued heating is then used to break up the strong inter molecular forces between molecules of the water such that the individual molecules are free to move about and due to the high temperature, have gained considerable amount of kinetic energy for the to rise to appreciable height and to also spread.
The heat which converts water into steam is called latent heat as during the boiling phase, the temperature of the water remains constant.
