Answer:
0.084 M
Explanation:
Using the Henderson-Hasselbalch equation for a buffer ( a buffer is solution contain a weak acid and it conjugate base; the solution resist change in pH)
pH = pKa + log ( base/acid)
4.9 - 4.76 =log ( base / acid)
10^0.14 = ( base / acid)
1.38 = (base / acid)
since there is 0.2 M in the buffer solution
the concentration of acid = 
× 0.2 = 0.084 M
Answer:
a. Electric Energy
b. Light Energy
c. Thermal Energy
Explanation:
a. When a lamp is turned on by means of a switch, electric energy is usually used, since that is the form of energy that is generated when there is a potential difference between two points, which allows to establish an electric current, that electric current travels through the wires up to the bulb of the lamp
b. In this case a case of light energy is presented since that is the energy transported by the light and that is manifested on the matter in different ways, one of them is to remove the electrons from the metals. This is what usually happens in some types of light bulbs, that when the displacement of the electrons is promoted, a beam of light is generated.
c. The last case is a case of thermal energy, since this energy is that expressed as the total kinetic energy resulting from the random movements of atoms and molecules. This was what could happen in case b, when the beam of light was generated. This energy is released in the form of heat, and may present high temperatures.
Answer:
Compounds are represented by chemical formulas.
Explanation:
atoms are made of 3 types of sub atomic particles; neutrons, protons and electrons
atomic number is the number of protons which is characteristic for the element. Atoms of the same element have the same number of protons.
mass number is the sum of the neutrons and protons.
Isotopes are atoms of the same element with different mass numbers. since they are the same element number of protons are the same but number of neutrons vary.
therefore 2 isotopes are of the same element so they have the same number of protons.
