Answer:
Atom is the smallest particle of matter.
Elements are made up of same atoms.
Atom consist of electron, proton and neutron.
Explanation:
Atom was first discovered by John Dalton.
word "Atom" came from Greek word, that means something that could not split. he explained that atom is indivisible particle.
In the end of 18th century J.J. Thomson put forward a new concept of atom. he said that atom have negative charged particles called electrons but overall atom is neutral.
In 1909 Rutherford with his students discovered positive charged particles and nucleus and said that it is in the center of atom.
He explain a model of atom and said that electrons revolve around a hard core in the center called nucleus.
In 1913 Niels Bohr explains the atomic spectra and put forward the concept of shells and sub-shells.
So overall Structure of an Atom is
- consist of Neutrons in nucleus
- +ve charged protons in nucleus
- A -vely charged electrons revolving around the nucleus
- the electron revolve in shells i.e. K, L, M, and N
- Each shell divide in sub-Shell such as s, p,d and f.
Atom has a specific atomic mass and atomic number
Atomic number = number of protons or electron
Atomic mass = number of protons + number of neutrons in nucleus.
Answer:
See explanation
Explanation:
The mechanism for the formation of bromohexane from hexene has been clearly shown in the image attached to this answer.
Hexene is attacked by HBr and a carbocation is first formed as shown. The carbocation is flat and planar. it can be attacked on either face by the bromide ion.
Attack on either faces yields a racemic mixture of the R and S enantiomer as shown in the image.
You can use the mechanism shown to fill in the structures.
Answer:
A
an element made of carbon and oxygen atoms.
Answer:
Explanation:
<u>1, Formula</u>
- Mass percent = (mass of solute/mass of solution) × 100
<u>2. Determine mass of solution</u>
Substitute the data and clear the mass of solution:
- 3.5 = (3.0g / mass of solution) × 100
- 0.035 = 3.0g / mass of solution
- mass of solution = 3.0 g / 0.035
- mass of solution = 85.714g
<u>3. Determine the mass of solvent:</u>
- mass of solvent = mass of solution - mass of solute
- mass of solvent = 85.714g - 3.0g = 82.714g
Round to two significant figures: 83 g
<span>When a chemical reaction occurs and the thermometer in the container records a drop in temperature t</span>he reaction is exothermic because heat was released by the reaction.
<span>B. The reaction is exothermic because heat was released by the reaction. is your answer.
Hoped I helped!</span>
