Answer:
of HA is 6.80
Explanation:

Acid dissociation constant (
) of HA is represented as-
![K_{a}=\frac{[H^{+}][A^{-}]}{[HA]}](https://tex.z-dn.net/?f=K_%7Ba%7D%3D%5Cfrac%7B%5BH%5E%7B%2B%7D%5D%5BA%5E%7B-%7D%5D%7D%7B%5BHA%5D%7D)
Where species inside third bracket represents equilibrium concentrations
Now, plug in all the given equilibrium concentration into above equation-

So, 
Hence 
The two elements that have the same properties as sodium are potassium and rubidium .
<h3>What is periodic table?</h3>
The periodic table is an arrangement of the elements in order of increasing atomic number.
From the list, the two elements that have the same properties as sodium are potassium and rubidium .
Proton has an atomic number of 20 and a mass number of 40. The number of electrons is the same as the number of protons. Given that the atomic number is the number of protons present, we have 20 electrons and 20 protons.
Number of neutrons = Mass number - Number of protons
= 40 - 20 = 20 neutrons
Learn more about periodic table:brainly.com/question/11155928
#SPJ1
Answer:
The correct option here is the first option
Explanation:
Covalent bond is the bond that involves the sharing of electrons between the participating atoms. The electrons (in the outermost shells of the atoms) that are involved this sharing are called the "shared pair" while those electrons (in the outermost shells of the atoms) that are not involved in this sharing are called the "lone pair". Bonding eventually leads to each of the participating atoms achieving it's octet configuration.
Carbon will bind covalently with fluorine (to form carbon tetrafluoride) with each of the electrons on the outermost shell of the carbon been shared covalently with fluorine atoms (that also requires just one electron to achieve it's octet configuration). Thus, at the end, we would have one carbon atom being covalently linked to four flourine atoms.
Answer:
B
Explanation:
its upside down but I'm 99% sure