Answer: Hydrogen and helium
Explanation:
Answer:
D. 44.2 g O₂
General Formulas and Concepts:
<u>Gas Laws</u>
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at <em>1 atm, 273 K</em>
<u>Stoichiometry</u>
- Dimensional Analysis
- Mole Ratio
Explanation:
<u>Step 1: Define</u>
<em>Identify given.</em>
61.9 L O₂ at STP
<u>Step 2: Convert</u>
We know that the oxygen gas is at STP. Therefore, we can set up and solve for how many <em>moles</em> of O₂ is present:

Recall the Periodic Table (Refer to attachments). Oxygen's atomic mass is roughly 16.00 grams per mole (g/mol). We can use a mole ratio to convert from <em>moles</em> to <em>grams</em>:

Now we deal with sig figs. From the original problem, we are given 3 significant figures. Round your answer to the <u>exact</u> same number of sig figs:

∴ our answer is letter choice D.
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Topic: AP Chemistry
Unit: Stoichiometry
Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example,
<span>in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some </span>
<span>insects (e.g. water striders) and even reptiles (basilisk) to run on the water surface. This property is caused by cohesion </span>
<span>of like molecules, and is responsible for many of the behaviors of liquids..</span>
B. electrons have a negative electrical charge
Answer:
As an object increases in speed, so does the amount of energy that it has, this energy is what we refer to as 'the increase in mass'
Explanation:
E