If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.
<u>Answer</u>:
the continents of earth were clustered together in formation that a scientist named Pangaea.
<u>Explanation</u>:
Before 300 million years ago, our earth was not made up of 7 different continent what we have now. Instead it was single huge mass land that was surrounded by a single ocean called Panthalassa. A lot of migration and collision lead to the formation of Pangaea. An Scientist named Albert Wegener gave the name Pangaea. Later, Pangaea was broken into Gondwanaland and Laurasia.These Lands were then divided into 7 continents.
Answer:
Organelles are structures within a cell that perform specific functions like controlling cell growth and producing energy. Plant and animal cells can contain similar types of organelles. However, certain organelles can only be found in plant cells and certain organelles can only be found in animal cells.
Answer:
- <em>1.34 × 10²⁴ molecules</em>
Explanation:
To calculate the <em>number of molecules of sodium oxide that will be created if 275 grams of sodium reacts with excess oxygen</em>, use the chemical equation to calculate the number of moles and then multiply by Avogadro's number.
<u>1) Balanced chemical equation (given):</u>
<u>2) Mole ratio:</u>
<u>3) Calculate the number of moles in 275 g of Na:</u>
- n = mass in grams / molar mass
- mass of Na = 275 g
- molar mass of Na₂O = 61.9789 g/mol
- n = 275 g / 61.9789 g/mol = 4.437 mol of Na
<u>4) Set a proportion to find the number of moles of product (Na₂O):</u>
- 2 mol Na₂O / 4 mol Na = x / 4.437 mol Na
- x = 4.437 / 2 mol Na₂O = 2.2185 mol Na₂O
<u>5) Convert the number of moles to number of molecules:</u>
- # molecules = n × 6.022 × 10²³ molecules/mol = 2.2185 mol × 6.022 × 10²³ molecules/mol = 1.34 × 10²⁴ molecules (rounded to 3 significant figures).
