Answer:
Explanation:
The following are the order of point from oldest to most recent
1. Atoms are tiny indivisible particles that make up all mater.
it is Postulate of Dalton's atomic theory. this theory was put forward in 1803
2. Negatively charged electrons are embedded in a mass of positive charge.
In 1897 J.J Thomson discovered that atom consist of tiny negatively charged particles called electrons that are uniformly spread in +vely charged matrix this model called as plum pudding model.
3. Atoms consist of mostly empty space with a dense nucleus of positive charge.
While doing experiment on gold foil Rutherford presented a model in 1909 and stated that atom consist mostly empty space with dense nucleus.
4. Electrons occupy specific energy levels surrounding a positively charged nucleus.
Niels Bohr in 1913 put forward a model to explain atomic orbitals/energy level. This is a postulate of Bohr model.
5. Electrons move about a positively charged nucleus in clouds that are defined by probabilities.
In 1926 Erwin Schrödinger explain the wave function of electrons and its probability.
Answer:
Explanation:
The given equation for the chemical reaction can be expressed as;
Using Hess Law to determine how much heat is produced by the decomposition of exactly 1 mole of H2O2 under standard conditions; we have the expression showing the Hess Law as follows:
At standard conditions;
the molar enthalpies of the given equation are as follows:
Replacing them into above formula; we have:
The above is the amount of heat of formation for two moles of hydrogen peroxide; thus for 1 mole hydrogen peroxide ; we have :
Hence; the heat produced after the decomposition of 1 mole of hydrogen peroxide is -54.04 kJ/mol
