Answer: C
Explanation:
Supermassive black holes are believed to be at the center of galaxies (to provide the huge gravitational force needed to keep the galaxy together).
Answer:
1. A substance 2. Valence
Explanation:
More liquid water will evaporate as it has enough energy to change state.
<u>Given :</u>
Mass of niobium (Nb) = 237 g
<u>To determine:</u>
The Number of moles of niobium in the given mass
<u>Explanation:</u>
In chemistry, moles (n) is a unit of measurement which is given by the ratio of the mass of the substance (m) to its atomic or molar mass (M)
i.e. n = 'm' in grams/ 'M' in grams.mole⁻¹
The atomic mass of Nb = 94 g/mol
Thus,
n = 237 g/ 94 g.mol⁻¹ = 2.521 moles
Ans: Number of moles of Nb rounded off to the nearest tenth is 2.5 moles