Bohr's model of the atom states that electrons orbit an atom's nucleus in electron shells of increasing energy. The electrons are free of physical contact with the nucleus, but are held in orbit due to the electrons' attraction to the oppositely charged protons in the nucleus.
Thomson's model, or the plum pudding model, it describes atoms as spheres of positively charged matter, in which electrons are embedded in.
The key difference is the locations of, and the motions of the electrons.
The average atomic mass of element X is 10.025 amu
The average atomic mass of element X = atomic mass of 10 isotope × relative abundance of 10 isotope + atomic mass of 11 isotope × relative abundance of 11 isotope + atomic mass of 12 isotope × relative abundance of 12 isotope
= 10 × 98% + 11 × 1.5 % + 12 × 0.5 %
= 10 × 0.98 + 11 × 0.015 + 12 × 0.005
= 9.8 + 0.165 + 0.06
= 10.025 amu
So, the average atomic mass of element X is 10.025 amu
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1st answer is The inner core is solid, the outer core is liquid, and the mantle is solid/plastic. 2 answe is helps test ideas and observe results.
Answer:
7.875 grams
Explanation:
You multiply 175 g by .045
This gives you 7.875 grams of lactose
Answer:
b) pH = 9.25
Explanation:
- NH4+(aq) + H2O(l) ↔ NH3(aq) + H3O+(aq)
- NH3 + H2O ↔ NH4+ + OH-
- 2 H2O ↔ H3O+ + OH-
⇒ Kb = [ NH4+ ] * [ OH- ] / [ NH3 ] = 1.86 E-5......from literature
mass balance NH4+:
⇒ M NH4+ = [ NH4+ ] - [ OH- ]
∴ [ NH3 ] ≅ M NH4+ = 0.26 M
⇒ Kb = (( 0.26 + [ OH- ] )) * [ OH- ] / 0.26 = 1.86 E-5
⇒ 0.26 [ OH-] + [ OH- ]² = 4.836 E-6
⇒ [ OH- ]² + 0.26 [ OH- ] - 4.836 E-6 = 0
⇒ [ OH- ] = 1.859 E-5 M
⇒ pOH = - Log ( 1.859 E-5 )
⇒ pOH = 4.7305
⇒ pH = 14 - pOH = 9.269