Electricity from renewable resources such as solar, geothermal, and wind generally does not contribute to climate change or local air pollution since no fuels are combusted.
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.
Complete Question:
What volume of hydrogen will be produced at STP by the reaction 67.3 g of magnesium with excess water according to the following reaction?
Mg + 2H₂O --> Mg(OH)₂ + H₂
Answer:
62 L
Solution:
Step 1: Calculate Moles of Mg as;
Moles = Mass / M.Mass
Moles = 67.3 g / 24.30 g/mol
Moles = 2.76 moles of Mg
Step 2: <u>Calculate Moles of H₂ as;</u>
According to balance chemical equation,
1 mole of Mg produced = 1 mole of H₂
So,
2.76 moles of Mg will produce = X moles of H₂
Solving for X,
X = 2.76 mol × 1 mol / 1 mol
X = 2.76 mol
Step 3: <u>Calculating volume of H₂,</u>
1 mole of ideal H₂ occupies = 22.4 L Volume at STP
So,
2.76 moles of H₂ will occupy = X L of H₂ at STP
Solving for X,
X = 2.76 mol × 22.4 L / 1 mol
X = 61.82 L ≈ 62 L
2Na + Cl2 ------>2 Na⁺Cl⁻
Na⁺Cl⁻ - sodium chloride
Two naturally occurring isotopes of antimony are shown in the pic with their abundance