<span>PbO
Let's look at each of the 4 compounds and see what's needed.
PbO.
* Oxygen has a valance shell that's missing 2 electrons and wants to get those 2 elections. Lead donates them, so you have a Lead (II) ions. This is a correct choice.
PbCl4
* Chlorine wants to grab 1 electron to fill it's valance shell and Lead donates that election. However, there's 4 chlorine atoms and every one of them wants and electron, and lead is donating all 4 of the desired electrons making the Lead (IV) ion. So this is a bad choice.
Pb2O
* Oxygen still wants 2 electrons and gets them from the lead. But there's 2 lead atoms and each of them donates 1 election making for 2 Lead(I) ions. So this too is a bad choice.
Pb2S
* Sulfur is in the same column of the periodic table as oxygen and if this compound were to exist would have similar properties as Pb2O and would have Lead(I) ions. So this is a bad choice.</span>
Answer:
B) All carbon atoms have 6 neutrons.
Explanation:
The false statement from the given choices is that all carbon atoms have 6 neutrons.
There is a phenomenon called isotopy in chemistry.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- These atoms of elements are called isotopes.
- Carbon atoms generally have proton number of 6 which is the same as the atomic number.
- As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.
For the isotopes of carbon, their number of neutrons differs.
For example:
<em>¹²₆C ¹³₆C ¹⁴₆C</em>
The number of neutrons differs in the above isotopes.
Number of neutrons = mass number - atomic number;
¹²₆C , number of neutrons = 12 - 6 = 6
¹³₆C, number of neutrons = 13 - 6 = 7
¹⁴₆C, number of neutrons = 14 - 6 = 8
Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.
Answer:
A chemical change has occurred, with energy being given off.
Explanation:
The liquids mix and the stick gives off energy in light form
Then we would not have oxygen because plants give oxygen in order to breathe
<span>The following is the role of NaCl and EDTA in DNA isolation, hope it helps:
NaCl provides Na+ ions that will block negative charge from phosphates on DNA.
Negatively charged phosphates on DNA cause molecules to repel each other. The Na+ ions will form an ionic bond with the negatively charged phosphates on the DNA, neutralizing the negative charges and allowing the DNA molecules to come together.</span>
