Km is the biggest measure in width (even if there are bigger measures like Mm, Gm, Tm).
1 Km = 1000 m, 100000 cm and 1000000 mm
Answer: option (1) an electron.
Justification:
1) The plum pudding model of the atom conceived by the scientist J.J. Thompson, described the atom as a solid sphere positively charged with the electrons (particles negatively charged) embedded.
2) The next model of the atom, developed by the scientist Ernest Rutherford, depicted the atom a mostly empty space with a small dense positively charged nucleous and the electrons surrounding it.
3) Then, Niels Bhor came out with the model of electrons in fixed orbits around the nucleous, just like the planets orbit the Sun. So, the path followed by the electrons were orbits.
4) The quantum model of the atom did not place the electrons in fixed orbits around the nucleous but in regions around the nucleous. Those regions were named orbitals. And they are regions were it is most probable to find the electron, since it is not possible to tell the exact position of an electron.
As per this model, the electron has a wave function associated. The scientist Schrodinger developed the wave equation which predicts the location of the electron as a probability.
The orbitals are those regions were it is most likely to find the electron. Those regions are thought as clouds of electrons.
Answer:
Explanation:
The equation of the reaction is given as:
3H₂ + N₂ → 2NH₃
Given parameters:
Number of moles of NH₃ = 8moles
Number of moles of H₂ = ?
Number of moles of N₂ = ?
Solution
From the balanced reaction equation, we can establish some mole ratios that would help solve the problem:
To find the number of moles of H₂;
The equation shows that:
2 moles of NH₃ were produced using 3 moles of H₂
therefore: 8 moles of NH₃ will be produced by 
= 12moles
So, 12 moles of hydrogen gas will react to give 8 moles of ammonia.
To find the number of moles of N₂
The equation shows that:
2 moles of NH₃ were produced from 1 mole of N₂
8 moles of NH₃ would be produced from 
= 4moles of Nitrogen gas
Therefore, 4moles of nitrogen gas would be produced
Answer: B) 46.7% Si and 53.3% O
Explanation:
To calculate the mass percent of element in a given compound, we use the formula:
Mass of quartz 
= 5.05 g
Mass of silicon = 2.36 g
Mass of oxygen = Mass of quartz - mass of silicon = 5.05g - 2.36 g = 2.69 g
Thus the percentages of silicon and oxygen in quartz are B) 46.7% Si and 53.3% O
