Answer:
protons and electrons
Explanation:
The symbol for an atom can be written to show its mass number at the top, and its atomic number at the bottom. To calculate the numbers of subatomic particles in an atom, use its atomic number and mass number: number of protons = atomic number. number of electrons = atomic number.
DNA
Nucleoulos
Nuclear Membrane
Here we have to choose the challenge which is faced by the scientist to make a hydrogen fuel cell by using water.
The challenge that the scientists are facing a. decomposition of water requires a high energy.
For the generation of fuel cells by hydrogen the use of water (H₂O) is a challenging task as the H-O bond in water is so strong and need high activation energy.
As per the mechanism of hydrogen fuel cell generation of H₂ is compulsory. Water remains in its solution as H₂O⇔H⁺ + OH⁻. The breaking of hydroxide ion (OH⁻) to form free hydrogen need a high energy, which cannot meet easily by any energy source.
The sun is always a renewable energy source as the energy of sun is infinitive.
The decomposition of water will only produce oxygen (O₂) and hydrogen (H₂) among which H₂ will be used in the fuel cell and O₂ is not at all harmful.
The excess O₂ is always good for the environment as it is the breathing source in the living system.
Answer:
The atomic mass of lead is: 207.216 u
Explanation:
data Isotopes mass percent
1 203.97302 1.4
2 205.974444 24.1
3 206.97587 22.1
4 207.97663 52.4
atomic mass = (203.97302x 0.014) + (205.974444 x 0.241) +
(206.97587 x 0.221) + (207.97663 x 0.524)
atomic mass = 2.856 +49.639 + 45.742 + 108.979
atomic mass = 207.216 u
Answer:
P³⁻ + Cl⁻ --> PCl₃
Explanation:
PCl₃: phosphorus trichloride. prefix in front of chloride is "tri"–meaning three.
