Answer:
helium , krypton,xenon,radon, argon are noble gasses
Answer:
P-block metals have classic metal characteristics like they are shiny, they are good conductors of heat and electricity, and they lose electrons easily. These metals have high melting points and readily react with nonmetals to form ionic compounds.
Explanation:
Answer:
n = 2.208x10¹⁸ photons
Explanation:
The energy of a photon( an elementary particle) is given by the equation:
E = nxhxf
Where n is the number of photons, h is plank constant (6,62x10⁻³⁴ J.s), and f is the frequency. Knowing that the power level is 0.120mW (1.2x10⁻⁴ W), the energy in J, for a time of 78 min (4680 s)
E = 1.2x10⁻⁴x4680 = 0.5616 J
The frequency of a photon is its velocity ( c= 3x10⁸ m/s) divided by its wavelength, which is 780 nm = 780x10⁻⁹ m
f = 3x10⁸/780x10⁻⁹
f = 3.846x10¹⁴ s⁻¹
Then, the number of photons is:
0.5616 = nx6,62x10⁻³⁴x3.846x10¹⁴
n = 2.208x10¹⁸ photons.
Answer:
ZnS(s) ⇄ S²⁻(aq) + Zn²⁺(aq)
Explanation:
First, we will write the molecular equation, since it is easier to balance.
2 HBr(aq) + ZnS(s) ⇄ H₂S(aq) + ZnBr₂(aq)
In the full ionic equation we include all ions and molecular species.
2 H⁺(aq) + 2 Br⁻(aq) + ZnS(s) ⇄ 2 H⁺(aq) + S²⁻(aq) + Zn²⁺(aq) + 2 Br⁻(aq)
In the net ionic equation we include only the ions that participate in the reaction and the molecular species.
ZnS(s) ⇄ S²⁻(aq) + Zn²⁺(aq)
Answer:
The right objective is A I guess
