Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 =><span> 8.72 mol</span>
<span>answer A</span>
Answer:
HS+Na=>NaS+1/2H2(here HS- acts as an acid)
HS-. + HCl=> H2S(g)+ Cl-(here HS- acts as a base)
The answer is 40.
We can solve this by finding out the number of protons, and neutrons. Atomic number of an element means the number of protons in that element. So, the atom has 30 protons if the atomic number is 30.
On the other hand, mass number is the total number of protons and neutrons, but not electrons, because they're too light comparing to the other 2. Therefore, we can simply solve the number of neutrons in the atom by subtracting the number of protons from the mass number. 70 - 30 = 40.
Therfore, the number of neutrons is 40.
Weathering is the physical or chemical process where rocks are
broken down to form sediments.
• Physical weathering does not change the rock’s composition.
• Chemical weathering does change the rock’s composition
• Erosion is the process where forces such as water, wind, ice, or gravity
transport sediments to some remote location
