Answer:
d. 0.208 M NaOH
Explanation:
M[NaOH] = 23+16+1= 40g/mol
2.40L = 2.4dm3
M=m/Mv
M=20.0g/40g/mol×2.4dm3
M=20.0g ÷ 96
M= 0.208 M NaOH
Answer:
a.
Turn paper Blue - these are alkaline/ base substances.
Turn paper Red - these substances are acidic in nature.
- Lemon Juice
- Vinegar
- Cola drink
b. i. A wasp sting - Lemon juice
ii. A bee sting - Toothpaste
iii. A wasp sting is alkaline which means that running an acidic substance like lemon or lemon juice on it should neutralize it.
A bee sting is acidic so an alkaline substance such as toothpaste should neutralize it as well.
The chemical formula of aluminium nitrate is - Al(NO₃)₃
cation is Al³⁺
anion is NO₃⁻
One Al atom binds to three nitrate groups
the options given are
2. <span>It has three aluminum (Al) atoms
this is incorrect as there's only one Al atom
3. </span><span>It has one NO3 group.
this is incorrect as there are three nitrate groups
4. </span><span>It has nine nitrogen (N) atoms
there are only 3 N atoms therefore this too is incorrect
</span>therefore the correct answer is -
It has three NO₃<span> groups
</span>
Answer:
The number of positive charges in nucleus of an atoms are equal to the atomic number and also positive charges are equal to the negative charges which are electrons in neutral atom.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e⁻
Mass= 9.10938356×10⁻³¹ Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Neutron and proton:
Neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P⁺
Symbol of neutron= n⁰
Mass of proton=1.672623×10⁻²⁷ Kg
Mass of neutron=1.674929×10⁻²⁷ Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.
