Answer:
2PO₄³⁻ + 3Fe²⁺ → Fe₃(PO₄)₂(s)
Explanation:
In a net ionic equation you list <em>only the ions that are participating in the reaction. </em>
When potassium phosphate, K₃PO₄, reacts with iron (II) nitrate, Fe(NO₃)₂ producing iron (II) phosphate, Fe₃(PO₄)₂ that is an insoluble salt. The reaction is:
2K₃PO₄ + 3 Fe(NO₃)₂ → Fe₃(PO₄)₂(s) + 6NO₃⁻ + 6K⁺
The ionic equation is:
6K⁺ + 2PO₄³⁻ + 3Fe²⁺ + 6NO₃⁻→ Fe₃(PO₄)₂(s) + 6NO₃⁻ + 6K⁺
Subtracting the K⁺ and NO₃⁻ ions that are not participating in the reaction, the net ionic equation is:
<h3>2PO₄³⁻ + 3Fe²⁺ → Fe₃(PO₄)₂(s)</h3>
Answer to this is Radioactive isotopes.
Isotopes are the species of the same element having different atomic masses that means the number of protons remains the same but number of neutrons do differ. For example 
and 
are the two isotopes of Hydrogen (
).
Radioactive isotopes are the isotopes which release some kind of energy in the form of alpha particles, beta particles or gamma radiation. Examples of each of the decay processes are :
Alpha Decay: In this decay one alpha particle having atomic mass 4 and atomic number 2 or we can say a He molecule will come out. 
Beta Decay: In this decay a 
particle is emitted increasing the atomic number of the reactant by 1 unit.
Gamma Radiation: In this type of reaction only radiation is emitted out which does not change the original molecule.
Answer:
E = 19.89×10⁻¹⁶ J
λ = 1×10⁻¹ nm
Explanation:
Given data:
Frequency of xray = 3×10¹⁸ Hz
Wavelength of xray = ?
Energy of xray = ?
Solution:
speed of wave = wavelength × frequency
speed = 3×10⁸ m/s
3×10⁸ m/s = λ ×3×10¹⁸ s⁻¹
λ = 3×10⁸ m/s / 3×10¹⁸ s⁻¹
λ = 1×10⁻¹⁰m
m to nm:
λ = 1×10⁻¹⁰m×10⁹
λ = 1×10⁻¹ nm
Energy of x-ray:
E = h.f
h = plancks constant = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js ×3×10¹⁸ s⁻
¹
E = 19.89×10⁻¹⁶ J
I am pretty sure it is B. If it turns litmus paper red it is acidic. The other 2 make no sense.
I might be wrong tho.
Hope that helped☺️
