Answer:
Scientists have been debating over light being a wave or particle since its recognition.
Sir Issac Newton discovered that light had frequency and other properties. Newton described light to be a particle because it created shadows which were sharp and very clear.
Francesco Maria Grimaldi, claimed that light was a wave. This was because this scientist observed the diffraction of light and hence, claimed light to be a type of wave.
The speed of light is 299 792 458 m / s. Nothing can travel faster than light.
Question options:
A) K2SO4
B) FeCl₃
C) NaOH
D) NH₃
E) KCl
Answer:
D. NH₃
Explanation:
K2SO4 = 2 K+ + SO42-
[K+]= 2 x 1.0 = 2.0 M ; [SO42-] = 1.0 M
total concentrations of ions = 2.0 + 1.0 = <em>3.0 M</em>
FeCl3 = Fe3+ + 3Cl-
[Fe3+] = 1.0 M ; [Cl-] = 3 x 1.0 = 3.0
total concentration ions = 1.0 + 3.0 =<em> 4.0 M</em>
NaOH = Na+ + OH-
[Na+] = [OH-] = 1.0 M
total concentration ions = 1.0 + 1.0 = <em>2.0 M</em>
<u>NH3 is a weak acid so the concentration of NH4+ and OH- </u><u><em>< 2.0</em></u>
KCl = K+ + Cl-
[K+] = [Cl-] = 1.0 M
total concentration ions = 1.0 + 1.0 =<em> 2.0 M</em>
Answer:
a) 
2 moles of Zinc sulphide in solid form reacts with 3 moles of Oxygen in gaseous form to give 2 moles of Zinc oxide in solid form and 2 moles of sulphur dioxide in gaseous form.
b) 
1 mole of calcium hydride in solid form reacts with 2 moles of liquid water to give 1 mole of calcium hydroxide dissolved in water and 2 moles of hydrogen in gaseous form.
The chemical reactions are written by writing the chemical formula of the reactants on left side of the arrow followed by chemical formula of the products. The number of atoms of each element must be balanced to follow the law of conservation of mass.