The answer would be C- both hydrogen and covalent bonds.
They are examples of elements because there's only one molecule in both
a light bulb is the example of chemical energy
Answer:
For ²⁰⁸Pb²⁺ cation, the sum of the number of neutrons and electrons = 206
Explanation:
Lead, chemical symbol Pb, is a chemical element which belongs to the group 14 of the periodic table. The atomic number of lead is 82 and it is a member of the p-block.
The isotope of lead with the mass number 208, has 126 neutrons.
Since, atomic number = number of protons = number of electrons for neutral atom
Therefore, for ²⁰⁸Pb: number of electrons= 82
So, <u>for ²⁰⁸Pb²⁺ cation: number of electrons</u>= 82 - 2 = 80
<u>Therefore, for ²⁰⁸Pb²⁺ cation, the sum of the number of neutrons and electrons = number of electrons + number of neutrons = 80 electrons + 126 neutrons = 206.</u>
GPE = mgh
Where GPE is gravitational potential energy (J), m is the mass ob the object (kg), g is acceleration due to gravity (m/s²) and h is the height (m)
m = 4 kg
g = 9.8 m/s²
h = 3 m
By substitution,
GPE = 4 kg x 9.8 m/s² x 3 m
= 117.6 J
≈ 118 J
Hence, the answer is D
