Answer:
A particle consisting of two neutrons and two protons, with a positive charge; emitted energetically from the nuclei of unstable isotopes of mass number 82 and up. Synonym(s): alpha ray. Helie, Louis T.
Answer:
C. 588 nm
Explanation:
Given parameters:
Energy of the photon = 3.38 x 10⁻¹⁹J
Unknown:
Wavelength of the photon = ?
Solution:
The energy of a photon can be expressed as;
E = 
hc = E x wavelength
Wavelength = 
h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s
c is the speed of light = 3 x 10⁸m/s
E is the energy
Wavelength = 
= 5.89 x 10⁻⁷m
Answer:
Na2S, (NH4)3PO4
Explanation:
We can decide what compounds are soluble by considering the solubility rules that apply.
CdCO3 is not soluble in water because all carbonates are insoluble except those of ammonium, sodium and potassium.
Na2S is soluble in water because all sulphides are insoluble except those of sodium, potassium and ammonium.
PbSO4 is insoluble in water because all sulphates are soluble except those of lead and barium. The sulphate of calcium is only slightly soluble in water.
(NH4)3PO4 is soluble in water because all phosphates are insoluble except those of sodium, potassium and ammonium.
Hg2Cl2 is insoluble in water because all chlorides are soluble except those of lead, mercury II and silver.
Answer:
Mass = 76.176 g
Explanation:
Given data:
Mass of lead(II) chloride produced = 62.9 g
Mass of lead(II) nitrate used = ?
Solution:
Chemical equation:
Pb(NO₃)₂ + 2HCl → PbCl₂ + 2HNO₃
Number of moles of lead(II) chloride:
Number of moles = mass/molar mass
Number of moles = 62.9 g/ 278.1 g/mol
Number of moles = 0.23 mol
Now we will compare the moles of lead(II) chloride with Pb(NO₃)₂ from balance chemical equation:
PbCl₂ : Pb(NO₃)₂
1 : 1
0.23 : 0.23
Mass of Pb(NO₃)₂:
Mass = number of moles × molar mass
Mass = 0.23 mol × 331.2 g/mol
Mass = 76.176 g
