Answer:
D =Average atomic mass = 10.801 amu.
5) True
Explanation:
Abundance of B¹⁰= 19.9%
Abundance of B¹¹ = 80.1%
Atomic mass of B¹⁰ = 10 amu
Atomic mass of B¹¹ = 11 amu
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (10×19.9)+(11×80.1) /100
Average atomic mass = 199 + 881.1 / 100
Average atomic mass = 1080.1 / 100
Average atomic mass = 10.801 amu.
2)A chemical reaction is one in which a new elements is created
True
False
Answer:
In chemical reaction new substances are created.
For example:
Photosynthesis:
It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.
Carbon dioxide + water + energy → glucose + oxygen
water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture by chloroplast.
Chemical equation:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen.
The World Is Too Much with Us" is a sonnet by the English Romantic poet William Wordsworth. In it, Wordsworth criticises the world of the First Industrial Revolution for being absorbed in materialism and distancing itself from nature. Composed circa 1802, the poem was first published in Poems, in Two Volumes (1807). Like most Italian sonnets, its 14 lines are written in iambic pentameter.
The answer is D.
"a heterogeneous mixture and a suspension"
Answer:
Zn(s) + Cu²⁺(aq) ⇒ Zn²⁺(aq) + Cu(s)
Explanation:
Let's consider the molecular single displacement equation between Zn and Cu(NO₃)₂
Zn(s) + Cu(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Cu(s)
The complete ionic equation includes all the ions and insoluble species.
Zn(s) + Cu²⁺(aq) + 2 NO₃⁻(aq) ⇒ Zn²⁺(aq) + 2 NO₃⁻(aq) + Cu(s)
The net ionic equation includes only the ions that participate in the reaction and insoluble species.
Zn(s) + Cu²⁺(aq) ⇒ Zn²⁺(aq) + Cu(s)
Answer:
4.6 mol Si
General Formulas and Concepts:
<u>Atomic Structure</u>
- Reading a Periodic Table
- Moles
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<u>Stoichiometry</u>
- Using Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
[Given] 2.8 × 10²⁴ atoms Si
[Solve] moles Si
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
- [DA] Set up:
- [DA] Divide [Cancel like units]:
<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs.</em>
4.64962 mol Si ≈ 4.6 mol Si
