Explanation:
Atoms can join together - they form bonds together - to make MOLECULES. ... For example, a hydrogen atom forms one bond, an oxygen atom forms two, and carbon forms four bonds. Look at that molecule of water again - each hydrogen has one bond, and the oxygen in the middle has two bonds. Molecules can be much bigger.
Answer:
3.18 (w/w) %
Explanation:
In the problem, you can find mass of NaClO knowing the reaction of NaClO with Na₂S₂O₃ is:
NaClO + 2Na₂S₂O₃ + H₂O → NaCl + Na₂S₄O₆ +2NaOH + NaCl
<em>Where 1 mole of NaClO reacts with 2 moles of Na₂S₂O₃</em>
<em> </em>Moles of thiosulfate in the titration are:
0.0101L ₓ (0.042mol / L) = 4.242x10⁻⁴ moles of Na₂S₂O₃
Thus, moles of NaClO in the initial solution are:
4.242x10⁻⁴ moles of Na₂S₂O₃ ₓ (1mol NaClO / 2 mol Na₂S₂O₃) = 2.121x10⁻⁴ moles NaClO
As molar mass of NaClO is 74.44g/mol, mass of 2.121x10⁻⁴ moles are:
2.121x10⁻⁴ moles ₓ (74.44g / mol) = <em>0.0158g of NaClO</em>
As mass of bleach is 0.496g, mass percent is:
0.0158g NaClO / 0.496g bleach ₓ 100 =
<h3>3.18 (w/w) % </h3>
A)2nd period - Li, Be, B,C,N,O,F,Ne
b)Metalls of the 2nd period are Li,Be
The correct answer is C because a Controlled Experiment tests only one factor at a time and consists of a control group and one or more experimental groups.
Answer:
1) Has a smaller radius than oxygen because of the increased electromagnetic attraction of the nuclei
2) Has a smaller radius than chlorine because all the electrons of F have lower energy levels and have less repulsion of other electrons and hence are more attracted to the nuclei .
Explanation:
Further the electrons are from the nuclei , the bigger the atomic radius is.
(+) attraction of electrons to the nuclei, (-) repulsion of the electrons away from the nuclei.
1) From O to F:
(+) there is one more proton --> Stronger positive charge of the nuclei means that the electrons are attracted more , then they come closer to it and therefore the radius decreases
(-) There is one more electron --> Every electron is repulsed by others away from the nuclei --> the radius increases. But this effect is not so strong because the new electron is added at the same energy level.
Overall the (+) effect is stronger than the (-) effect --> Radius decreases from O to F
2) From F to Cl
(+) there is one more protons --> Same effect as before
(-) There is one more electron --> Every electron is repulsed by others away from the nuclei. But this time the new electrons have a higher energy level --> Meaning that they are less attracted and hence the radius increases.
And also the other inner layers of electrons (electrons of lower energy levels) repulse this new external layer of electrons more effectively than the case of O --> Strong repulsion effect (called electron shielding effect) --> Radius increases
Overall the (-) effect is stronger than the (+) effect --> Radius increases from F to Cl (or decreases from Cl to F)
