Answer:
20.0 grams
Explanation:
If the density of gold is 20.0 g/mL, then we can multiply it by 1 mLto find the weight of 1 mL of gold.
20.0
*1mL=20.0 grams
Answer:
The use of phenol (carbolic acid) as a wound disinfectant was first practiced by Lister. The correct option is E
Explanation:
Phenol( carbolic acid) is an aromatic organic compound. It has the following properties:
- it's soluble in water
- it's a weak acid and
- highly reactive toward electrophilic aromatic substitution
In Medical field, phenol was first used as an antiseptic by Joseph Lister.Joseph Lister was a student at University College London under Robert Liston, later rising to the rank of Surgeon at Glasgow Royal Infirmary. He believed that patients who passed through surgery, died due to infections caused by microorganisms.He theorized that if germs could be killed or prevented, no infection would occur. Lister reasoned that a chemical could be used to destroy the micro-organisms that cause infection. He made use of the carbolic acid by soaking a clean cloth in them, and placing it over the surgical wounds of patients.
Answer: The pH will be 3.87
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)

According to stoichiometry,
1 mole of
gives 1 mole of
Thus
moles of
gives =
moles of
Putting in the values:
![pH=-\log[0.000134]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5B0.000134%5D)

Thus the pH will be 3.87
Answer:

Explanation:
Group 4A contains a total of 4 electrons for each atom in their valence shell. Filling the orbital diagram, let's say, for carbon, notice that when we start with period 2, we have two elements in the s-block, that is, lithium and beryllium. They correspond to the two s electrons that belong to the valence shell of carbon.
Moving on, we have boron and carbon, the remaining 2 electrons. Now, starting with boron, we're in the p-block.
That said, looking at the second period, the electron configuration for the valence shell of a group 4A element would be:
