Answer:
A
Explanation:
To label an element correctly using a combination of the symbol, mass number and atomic number furnishes some important information about the element.
We can obtain these information from the element provided that correct labeling of the element is presented. Firstly, after writing the symbol of the element, the atomic number is placed as a subscript on the left while the mass number of the atomic mass is placed as a superscript on the same left.
Looking at the question asked, we have the element symbol in the correct position as Ca, with 42 also in the correct position which is the mass number. The third number which is 20 is thus the atomic number of the element.
Answer:
Equal number of atoms of each gas in each container
Explanation:
When the valves opened, the two contaienrs become one and the gases beging to mix by diffusion. This phenomenom is produced by the differeces of concentration of a gas between two points of the container.
The gases will continue diffunding util their concentration in both containers are equal.
Answer: I have the same test message me
Explanation: it won’t let me share my answers
Answer: 18.0152 milliliters
Explanation:
Hi, to answer this question we have to apply the next formula:
Water volume = water mass / water density
Since 1 mol of water weights 18.0152 grams
Replacing with the values and solving:
Water volume = 18.0152 g / 1 g /ml = 18.0152 milliliters
Feel free to ask for more if needed or if you did not understand something.
Answer:
56.28 g
Explanation:
First change the grams of oxygen to moles.
(50.00 g)/(32.00 g/mol) = 1.5625 mol O₂
You have to use stoichiometry for the next part. Looking at the equation, you can see that for every 2 moles of H₂O, 1 mole of O₂ is produced. Convert from moles of O₂ to moles of H₂O using this relation.
(1.5625 mol O₂) × (2 mol H₂O/1 mol O₂) = 3.125 mol H₂O
Now convert moles of H₂O to grams.
(3.125 mol) × (18.01 g/mol) = 56.28125 g
Convert to significant figures.
56.28125 ≈ 56.28
