Answer:
The answer is
<h2>1.61 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 12.9 g
volume = 8 cm³
The density of the block is
We have the final answer as
<h3>1.61 g/cm³</h3>
Hope this helps you
The moon affects the tide. the sun affect the weather like polar attraction
answer:
1) reaction is exothermic
2) some bonds are broken and some are formed (see explanation below)
Explanation:
When energy is written on the product side of a chemical reaction, means that the energy is appearing as consequence of the reaction, that is a released energy (heat) that heats the surroundings.
This kind of reaction where heat is released and, as a consequence, the temperature of the surroundings increase, is called exothermic.
In every chemical reaction some bonds are broken and others are formed.
Breaking bonds requires energy.
Forming bonds release energy.
The energy written on the chemical reaction is a net change of energy: the bonds broken on the reactant side used energy and bonds formed on the products side released energy.
When the energy released by the formation of the product is greater than the energy of the bonds broken on the reactant side, the chemical reaction is exothermic.
Answer:
Take E(alpha particle energy) = 5.5 MeV (5.5x106x1.6x10-19)
If the charge on the lead nucleus is +82e(atomic number of lead is 82) = +82x1.6x10-19 C and the charge on the alpha particle is +2e = 2x1.6x10-19 C
Using dc = (1/4πεo)qQ/Eα we have
dc = [9x10^9x(2x1.6x10-19x82x1.6x10-19)]/5.5x10-13 = 6.67x10^-13m. = 6.67 x 10^-13 x 10^15 = 6.67 x 10^2fm
Note: 1meter = 10^15fentometer
Explanation:
This is well inside the atom but some eight nuclear diameters from the centre of the lead nucleus.