The Curies discovered radium
Answer:
They came from the element factories we call stars. Stars are mostly hydrogen throughout most of their lifespans. They are driven by massive and continuous thermonuclear reactions and gravity. ... This extra heat begins to fuse helium atoms into heavier elements like carbon and oxygen and gives new life to the star.
Explanation:
Answer:
Tea is a solution of compounds in water, so it is not chemically pure.
Explanation:
It is usually separated from tea leaves by filtration. B Because the composition of the solution is uniform throughout, it is a homogeneous mixture.
Answer:
Mg(s) +<em> 2</em> HCl (aq) → H₂(g) + MgCl₂
0.415g of H₂(g) <em>-Assuming mass of Mg(s) = 10.0g-</em>
Explanation:
Balancing the reaction:
Mg(s) + HCl (aq) → H₂(g) + MgCl₂
There are in products two atoms of H and Cl, the balancing equation is:
Mg(s) +<em> 2</em> HCl (aq) → H₂(g) + MgCl₂
<em>Assuming you add 10g of Mg(s) -Limiting reactant-</em>
<em />
10g of Mg are (Atomic mass: 24.305g/mol):
10g × (1 mol / 24.305g) = <em>0.411 moles of Mg</em>
<em>-Theoretical yield is the amount of product you would have after a chemical reaction occurs completely-</em>
Assuming theoretical yield, as 1 mole of Mg(s) produce 1 mole of H₂(g), theoretical yield of H₂(g) is 0.411moles H₂(g). In grams:
0.411mol H₂(g) × (1.01g / mol) = <em>0.415g of H₂(g)</em>
