14.skeptical
15.inference
16-invention
The density of pure gold (au) is 19.3 g/cm3. what is the mass of a block of gold that measures 1.2 cm x 5.00 cm x 3.20 cm? please show work.
Given: Density of pure gold = 19.3 g /cm^3
Measurement of block of gold =1.2 cm x 5.00 cm x 3.20 cm
To calculate : mass of gold
Formula used: Density = Mass / Volume
Volume = 1.2 cm x 5.00 cm x 3.20 cm = 19.2 cm^3
Mass of gold = Density X volume = 19.3 g /cm^3 X 19.2 cm^3 = 370.56 g
PbCl₂(aq) → Pb²⁺(aq) + 2Cl⁻(aq)
NaCl(aq) → Na⁺(aq) + Cl⁻(aq)
Pb²⁺(aq) + 2Cl⁻(aq) ⇄ PbCl₂(s)
At increase the concentration of chloride ions - concentration of lead ions decreases, the lead chloride is formed.
Positron emission = emission of a positron and a neutrino when a
proton is convert into a neutron. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
It's a spontaneous reaction for some nucleus.
eg:
Positron = e+
Neutrino=ve
O-15 --> N-15 + e+ +ve
Electron
capture= A nucleus absorb an electron while a proton is convert in a
neutron and emit a neutrino. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
eg:
Al-26 +e- --> Mg-26 + ve
Electron
capture and positron emission are two mechanisms to explain the decay
of some unstable isotopes. Electron capture is usually observed when the
energy difference between the initial and final state is low. Mainly
because of the larger amount of kinetic energy need for the expulsion
two particles with the positron emission mechanism.
