We can use the magnification equation for this problem.
Magnification equation:
<em>hi/h0 = di/d0</em>
Where in <em>hi </em>: image size, <em>h0</em> : object size, <em>di </em>: image distance, <em>d0 </em>: object distance from mirror
So plugging in the given variables we will have the corresponding equation
0.1 m / 0.3 m = <em>di / </em>0.4 m
<em>di</em> = 0.1333333m
The generated image of the object is located 0.13 meters or 13 cm away from the mirror
<span>John Dalton introduced a theory proposing that elements vary because of the mass of their atoms.
He said in his theory that all matter is made up of indivisible blocks called atoms. He also stipulated in his theory that elements are identical thus, have different sizes and masses.
Dalton's theory was different from Niels Bohr who proposed a new atomic model which was also commonly known as the modern atomic theory. Bohr's theory says that atoms are arranged in circular orbits around the nucleus. He patterned his model as the solar system.
</span>
Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 => 8.72 mol
answer A