1. inner core
2. outer core
3. mantle
4.crust
Given :
Mass of gold ( Au ) is 212 gram.
To Find :
Atoms of gold present in 212 gram of gold.
Solution :
Molecular mass of gold is 197 gram.
So, number of moles of gold in 212 gram is :
Now, we know 1 mole of any element contains 
atoms.
So, number of atoms present in 1.076 moles are :
Hence, this is the required solution.
Answer:
The compound you will use is the Dibasic phosphate
Explanation:
Simple phosphate buffer is used ubiquitously in biological experiments, as it can be adapted to a variety of pH levels, including isotonic. This wide range is due to phosphoric acid having 3 dissociation constants, (known in chemistry as a triprotic acid) allowing for formulation of buffers near each of the pH levels of 2.15, 6.86, or 12.32. Phosphate buffer is highly water soluble and has a high buffering capacity,
In this case the most efficient way is to disolve the dibasic compound which in the reaction with the water will form the monobasic phosphate.
To make the buffer you have to prepare the amount of distillate water needed, disolve the dibasic phospate, and then adjust with HCl or NaOH depending on the pH needed.
Answer: (3) They have different masses and the same charges.
Explanation:
Atoms are mainly composed of three main types of particles (in fact there are more particles that are smaller and make up these main particles): electrons, protons and neutrons.
In the specific case of <u>electrons</u> and <u>protons</u>, <u>both have the same charge, but electrons have the opposite sign</u>. This means a proton has an electric charge of +1 and an electron has an electric charge of −1.
On the other hand, <u>protons have more mass than electrons.</u> In fact, thetex]mass of an electron is about approximately 
the mass of a proton, this means these negative charged particles contribute almost nothing to the total mass of an atom (unlike protons, which together with neutrons, make up virtually all of the mass of an atom).
However, each atom that is electrically neutral has the same quantity of electrons as protons.
Answer:
Not balance.
Explanation:
Chemical equation:
K + Cl₂ → KCl
The given equation is not balance because there are one potassium and two chlorine atoms on left side of equation while on right side there are one potassium and one chlorine atom present.
Balance chemical equation:
2K + Cl₂ → 2KCl
the equation is balance now because there are two potassium and two chlorine atoms on left side of equation and two potassium and two chlorine atoms are also present on right side.
