Answer:
1.Most metal oxides are insoluble in water but some of these (e.g. Na2O.
Explanation:
2.: (i) A hissing sound is observed.
1.ii) The mixture starts boiling and lime water is obtained.
Answer:
e. 18
Explanation:
A neutral P atom has an atomic number of 15, which means there are 15 protons in the atom. In order to be neutral, the P atom must also have 15 electrons.
The P³⁻ anion has 3 electrons more than the neutral P atom since it has a charge of -3.
Thus, the total number of electrons are 15 + 3 = 18 electrons.
Answer:
a) Mg
b) Cl
c) Mn
d) Ne
Explanation:
This electron configuration for the atom in its excited state violates the Aufbau principle or rule like we have above.
Aufbau principle states "that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels."
We however can know and identify which element is in the excited state by knowing the sum of the electron that spread across the orbital and matching it up with the atomic number of the element in the periodic table.
14.5 M
Molarity=grams/liters
M=58/4.0
Answer:
The acronym is used to remember evidence of a chemical change.
Explanation:
P=precipitate
U=unexpected color change
F=fizzing
A=aroma
R=replaced by a new substance
T= temperature change
