Answer:
The smallest particle of a chemical element can be defined as an atom.
Explanation:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge.
a single electron or one of two or more electrons in the outer shell of an atom that is responsible for the chemical properties of the atom is known as valence electrons.
An atom's reactivity is its tendency to lose or gain electrons. ... This is because they have one outer electron and losing it gives them the stability of a outer electron shell as the next level... The reactivities of elements can be predicted by periodic trends.
Answer:
b) 3.10
Explanation:
HF ⇄ H
+ + F
Using Henderson-Hasselbalch Equation:
pH = pKa + log [A-]/[HA].
Where;
pKa = Dissociation constant = -log Ka
Hence, pKa of HF = -log 7.2 x 10^-4 = 3.14266
[A-] = concentration of conjugate base after dissociation = moles of base/total volume
= 0.15 x 0.3/0.8
= 0.05625 M
[HA] = concentration of the acid = moles of acid/total volume
= 0.10 x 0.5/0.8
= 0.0625 M
Note: <em>Total volume = 500 + 300 = 800 mL = 0.8 dm3</em>
pH = 3.14266 + log [0.05625/0.0625]
= 3.14267 + (-0.04575749056)
= 3.09691250944
<em>From all the available options below:</em>
<em>a) 2.97
</em>
<em>b) 3.10
</em>
<em>c) 3.19
</em>
<em>d) 3.22
</em>
<em>e) 3.32</em>
The correct option is b.
Answer:
10
Explanation:
In image
Take atomic mass or molar mass
of Al =27
Answer:
c. Can't decide with information given.
Explanation:
The chemical and physical processes can be classified as endothermic or exothermic. The first one happens when the system absorbs heat, so the temperature of the surroundings will decrease, and the other one happens when the system releases heat, then the temperature of the surrounds will increase.
Precipitation is the formation of a solid in a solution. The process can happen with absorption or release of heat, it depends on the substance. So, with the information given it's impossible to say it.
