Answer:
Answer in explanation
Explanation:
An atom of iron having an atomic number of 26 means there are 26 protons in the nucleus of the iron atom. This also means that for an electrically neutral atom of iron, there are 26 electrons orbiting the nucleus of the iron atom.
Factually, this also means that the atom iron occupies the position of the 26th element on the periodic table. Going forward, we can also say that the proton number of the iron element is 26.
The ratio of the measure of the central angle to the entire circle measure is 1/2
The area of the entire circle is 36
The area of the sector is 18
We use the Boyle's law to solve this question. At constant temperature, the volume of a fixed mass of a gas is inversely proportional to its pressure. When comparing the fixed mass of gas at different conditions under this law, the expression below is used.
P₁V₁=P₂V₂
P₁=5.0 atm
P₂=7.0atm
V₁=3.5 L
V₂=V
5.0×3.5=7.0×V
V= (5.0×3.5)7.0
V=2.5 L
Answer:
The third reaction
(2NaOH + NiCL2 ---> 2NaCl + Ni(OH)2)
Explanation:
By definition, a precipitation reaction refers to the formation of an insoluble salt when two solutions containing soluble salts are combined.
(Source: lumenlearning)
From the 4 options, we can eliminate the first and second one immediately because there is no formation of an insoluble salt.
Then, the last one can also be eliminated because even though there is insoluble solid formed, but it is not a salt, and, the reactants are not solutions too. In fact, the last one is a displacement reaction. A more reactive metal displaces a less reactive metal to form an ion.
Since the third reaction matches the definition of precipitation reaction, this is the answer.