Answer:
Noble gases
Explanation:
The noble gases are non-metals that requires the highest amount of energy to remove an electron from their shells.
The reason for this difficult is that their electronic configuration confers a stable configuration them.
- The ionization energy is the energy required to remove the most loosely held electrons in an atom.
- Due to the special stability of noble gases, it is very difficult to remove electrons from an atom of noble gases.
Explanation:
Sublimation is defined as a process in which solid state of a substance directly changes into vapor or gaseous state without undergoing liquid phase.
For example, naphthalene balls show sublimation at room temperature.
As this process does not cause any change in chemical composition of a substance. Hence, it is known as a physical process.
Similarly, when 
sublimes readily at 
. This shows change in physical state of carbon dioxide is taking place, i.e, from solid to gaseous phase.
Thus, we can conclude that when sublimes readily at then it means physical properties are usually associated with a compound that undergoes this kind of change.
Answer: v = 2π2 Kme2 Z / nh
Explanation:
The formula for velocity of an electron in the nth orbit is given as,
v = 2π2 Kme2 Z / nh
v = velocity
K = 1/(4πε0)
m= mass of an electron
e = Charge on an electron
Z= atomic number
h= Planck’s constant
n is a positive integer.
Answer:
The correct answer is "three groups of plants—a group fertilized by X, a group fertilized by Y, and a control group with no fertilizer".
Explanation:
I had to look for the problem to know the options.
The best way to determine which fertilizer is most effective is to have three evaluation groups. One group will be tested with fertilizer X and another with fertilizer Y. By leaving the third group without applying fertilizer, this will be the general pattern for comparing the effectiveness of the other two.
Have a nice day!
If the solution is BASIC than it will turn purple but if ACIDIC it will turn pink.
