Answer:
1045
Answer: 1045 J of energy was released on cooling the down the water from 20 °C to 10 °C.
Answer:
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary for us to set the equation for the calculation of density and mass divided by volume:
Thus, we can find the mass of the unknown by subtracting the total mass of the liquid to the mass of the flask and the liquid:
So that we are now able to calculate the density in g/mL first:
Now, we proceed to the conversion to lb/in³ by using the following setup:
Regards!
Mass = mr x moles
Mr of CuCl2 = ( 63.5) + ( 35.5 x 2) = 134.5
2.5 = 134.5 x moles
2.5 / 134.5 = moles
Moles = 0.019 (2DP)
0.25g of Al
Mr of Al = 27
0.25 = 27 x moles
0.25/ 27 = 0.0093 moles (2sf)
Hope this helps :)
Answer:
Boron
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
In given atomic model we can see that there are five electrons out side the nucleus it means this atomic model is of that element which have atomic number 5 and it is boron.
It has 5 electron 5 proton and 6 neutrons.
It means its atomic number is five and mass number is 5+6 = 11