18. Reaction will occur.
19. Reaction Will occur.
20. Reaction will occur.
21. Reaction will occur.
22. Reaction won't occur.
23. Reaction will occur.
24. Reaction will occur.
25. Reaction won't occur.
<h3><u>Explanation</u>:</h3>
The reaction rate of the metals with water, steam, acid, or hydroxides or their inert behavior towards them are noted in the metal activity series.
It contains all the metals one after the other which and the upper metal can replace the lower metal from its salt.
Calcium can replace hydrogen from acid, so the reaction will occur in 18. The products formed are calcium phosphate and hydrogen gas.
Chlorine is more reactive than bromine. So it can replace bromine from its salt to from bromine gas and magnesium chloride.
Aluminium can replace iron from its salt. So it will form aluminium oxide and iron metal. This reaction is used to obtain iron from ores.
Zinc can replace hydrogen from acid. So the products will be zinc chloride and hydrogen gas.
Chromium cannot displace hydrogen form water. So the reaction won't occur.
Tin can replace hydrogen form acid. So the reaction will proceed.
Magnesium will replace platinum from its salt. So magnesium oxide and platinum will form.
Bismuth cannot replace hydrogen from acid. So the reaction won't proceed.
the answer is c
Explanation:
because c has all elements mixed together
Answer: The half-life of a first-order reaction is, 
Explanation:
All the radioactive reactions follows first order kinetics.
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 440 s
= initial amount of the reactant = 0.50 M
[A] = left amount = 0.20 M
Putting values in above equation, we get:


The equation used to calculate half life for first order kinetics:

Putting values in this equation, we get:

Therefore, the half-life of a first-order reaction is, 
The hybridization for the Br in BrO4⁻ is
. So, the correct option is (e).
In chemistry, the idea of combining atomic orbitals to create new hybrid orbitals (with different energies, shapes, etc., than the component atomic orbitals) is known as orbital hybridisation (or hybridization). These new hybrid orbitals are suitable for the pairing of electrons to form chemical bonds in valence bond theory.
Because more directional hybridised orbitals result in higher overlap when creating bonds, stronger bonds are formed, which favours the hybridization of orbitals. When hybridization takes place, this leads to more stable molecules.
One s orbital and three p orbitals combine to form four
orbitals, each of which has a 25% s character and a 75% p character. This process is known as
hybridization. Anytime an atom is surrounded by four groups of electrons, this kind of hybridization is necessary.
Learn more about hybridization here:
brainly.com/question/12207339
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