Atomic mass Ca = 40 a.m.u
1 mole Ca ----------- 40 g
2.5 mols Ca -------- ( mass Ca )
Mass Ca = 2.5 x 40 / 1
Mass Ca = 100 / 1
= 100 g of Ca
hope this helps!
Answer:
1
Explanation:
Using the Rydberg formula as:
where,
λ is wavelength of photon
R = Rydberg's constant (1.097 × 10⁷ m⁻¹)
Z = atomic number of atom
n₁ is the initial final level and n₂ is the final energy level
For Hydrogen atom, Z= 1
n₂ = 2
Wavelength = 410.1 nm
Also,
1 nm = 10⁻⁹ m
So,
Wavelength = 410.1 × 10⁻⁹ m
Applying in the formula as:
Solving for n₁ , we get
n₁ ≅ 1
Answer:
B) a substance's color and odor changed Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.
The important thing to note is the reason why electron react is due to the instability of the electrons. All elements wants to aim the electron configuration of the noble gases. This is the most stable form in which each of the orbitals are sufficiently filled. When it comes to bonding, the order of reactivity is: alkynes > alkenes > alkanes. Alkynes are compounds with triple bonds, alkenes with double bonds and alkanes with single bonds. The single bonds are called saturated hydrocarbons. This is because they have reached stability, so it is quite difficult to react this with reducing or oxidizing agents. Alkynes and alkenes are unsaturated hydrocarbons. They readily react with reducing and oxidizing agents so as to become saturated, as well. The underlying principle for this is that single bonds contain sigma bonds which is the head-on overlapping of electrons. These is the strongest type of covalent bond. Double and triple bonds contain pi bonds which is the side overlapping of electrons orbitals. Hence, these electrons would be easily separated making it more reactive especially during protonation.
Answer:
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The electric light bulb didn't appear from efforts to develop better candles or telling people to use less light.
