49 neutrons in each nucleus.
<h3>Explanation</h3>
For each nucleus:
Mass number = Number of protons + Number of neutrons.
The atomic number of a nucleus is the same as its number of protons. The atomic number of the nucleus here is 31. There are 31 protons in each nucleus.
- Mass number = 80;
- Number of protons = Atomic number = 31;
- The number of neutrons is to be found.
Again,
Mass number = Number of protons + Number of neutrons.
80 = 31 + Number of neutrons.
Number of neutrons = 80 - 31 = 49.
A dependible common measurement
Ionic bond is a chemical bond formed by the complete transfer of electrons between two atoms. The atom that loses electrons gains a positive charge (cation) and that which accepts electrons gains a negative charge (anion). Now, electronegativity is a parameter that measures the tendency of an atom to accept electrons. In the context of ionic bonding, two elements which show a significant difference in their electronegativity values form ionic bonds.
In the given examples, the difference in electronegativity is greatest between K and Br i.e. 0.8 and 2.8 respectively with a difference of 2.0. This also makes sense since K and Br are on the extreme ends of the periodic table. Hence, potassium with a valence electron configuration of 4s1 will lose its s electron to Br (4s24p6) and form an ionic molecule K⁺Br⁻
Ans E) potassium and bromine
b) LiH (s) + H₂O (l) --> LiOH (aq) + H₂ (g)
When an alkali metal reacts with water it always produces the metal hydroxide and hydrogen gas which is liberated into the air.
2M(s)+2H₂O (l) →2MOH (aq)+ H₂ (g)
Lithium reacts with water very vigorously.
Alkali metals need to be stored under oil to prevent them from reacting with the oxygen and water vapour in the air. The reactivity of the alkali metals increases down the group.
Alkali metals consist of the following metals:
Lithium, sodium, potassium, rubidium, caesium.
Lithium, sodium and potassium also react vigorously with water and produce hydrogen gas and which is liberated in the air.
To know more about exothermic reactions, refer to this link:
brainly.com/question/10373907
#SPJ4
Answer:
12. 2.9 g= 0.0029 13. 14.7 L = 14700 ml
14. The chemical formula of magnesium hydroxide is Mg(OH)2, and its molar mass is 58.32 g/mol.
Explanation: