Answer:
d. 
Explanation:
Mass of calcium = 4.00 g
Molar mass of calcium = 40.078 g/mol
<u>Moles of calcium = 4.00 / 40.078 moles = 0.9981 moles</u>
Given that the compound only contains calcium and bromine. So,
Mass of bromine in the sample = Total mass - Mass of calcium
Mass of the sample = 20.0 g
<u>Mass of bromine in sample = 20.0 - 4.00 g = 16.0 g</u>
Molar mass of bromine = 79.904 g/mol
<u>Moles of Bromine = 16.0 / 79.904 = 0.2002 moles
</u>
Taking the simplest ratio for Ca and Br as:
0.9981 : 0.2002 = 5 : 1
The empirical formula is =
Answer:
Neptunium, Protactinium, plutonium and more
Explanation:
Answer:
The correct answer is C 112
Explanation:
I just took the test good luck :)
Answer: Correct option is (D).
Explanation:
Given that unknown element has larger atomic radii than potassium atoms and its valence electrons feel an effective nuclear charge of +1 which means that this unknown element belongs to group(I) of the periodic table.
In periodic table:
- As we move down the group the value of ionization energy decreases down the group. This is due to increase in the size of an element.With increase in size valence electrons gets far away from the nucleus by which less energy will require to ionize the element.
- Electronegative characters also decreases when we move down the group.This is due to increase in size of an element by which electrons present in valence shells are far away from the nucleus.
So,It would have lower ionization energies than K and a lower electronegativity value than K.
Each orbit holds a fixed number of electrons, the n=1 orbit can only hold two electrons
