Answer:b
Explanation:
When a covalent bond is nonpolar, it implies that there is a symmetric distribution of the electron cloud between the the two nuclei. That is, the electron cloud of the shared pair is positioned equidistant from the two bonding atoms. In this case, the both atoms attract electrons equally and the molecule lacks a permanent dipole.
A proton is positive energy, a neutron is neutral, and an electron is negative charge. Protons and neutrons are in the nucleus of an atom and electrons are on the electron cloud.
Answer:
Celsius is currently a derived unit for temperature in the SI system, kelvin being the base unit. ... The two main reference points of the Celsius scale were the freezing point of water (or melting point of ice) being defined as 0 °C and the boiling point of water being 100 °C.
Explanation:
Hope it helps
Given, half life of a certain radioactive element = 800 years.
Amount of substance remaining at time t = 12.5%
Lets consider the initial amount of the radioactive substance = 100%
Using the half life equation:
A = A₀(1/2)^t/t₁/₂
where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.
Plugging the given data into the half life equation we have,
12.5 = 100 . (1/2)^t/800
12.5/100 = (1/2)^t/800
0.125 = (0.5)^t/800
(0.5)^3 = (0.5)^t/800
3 = t/800
t = 2400 years
Thus the object is 2400 years old.
The number of moles of one substance given the amount in mass can be calculated by the use of the molar mass. This is the mass of a compound per 1 mol of the said substance. For, KCl the molar mass is 74.55 g/ mol
148 g / 74.55 g/mol = 2 mol KCl
Hope this answers the question. have a nice day.
