First, we determine the energy released by the reaction using the heat capacity and change in temperature as such:
Q = cΔT
Q = 32.16 * 0.42
Q = 13.51 kJ
Next, we determine the moles of ammonia formed as the heat of formation is expressed in "per mole".
Moles = mass / molecular weight
Moles = 5/17
Moles = 0.294
Heat of formation = 13.51 / 0.294
The heat of formation of ammonia is 45.95 kJ/mol
atoms are made of 3 types of sub atomic particles- protons, neutrons and electrons
from these 3 particles, electrons are responsible for participating in chemical bonds. therefore chemical properties of elements are based on the number of electrons present.
valence electrons are the number of electrons in the outermost energy shell that are involved in chemical bonds.
atoms with same number of valence electrons are grouped in to columns called groups.
therefore elements of the same group have same number of valence electrons, hence similar chemical properties.
from the options given
only Be and Mg belong to the same group they both belong to group 2 with 2 valence electrons
therefore Be and Mg have similar chemical properties
answer is
1) Be and Mg
This certain type of rock is constructive, not only from the fact that it was made up from earthly habits. But also it breaks down very easily, which can help the environment. Therefore a sedimentary rock is constructive.
Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = 
For the 4.12 g sample
Moles of a substance is given by
Number of molecules is given by
For the 19.37 g sample
Number of molecules is given by
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
I would say the first three. But I'm not 100% sure. I'm truly sorry if it's wrong
