Answer:
Niels Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. This atomic model was the first to use quantum theory, in that the electrons were limited to specific orbits around the nucleus.
Ernest Rutherford is known for his pioneering studies of radioactivity and the atom. He discovered that there are two types of radiation, alpha and beta particles, coming from uranium. He found that the atom consists mostly of empty space, with its mass concentrated in a central positively charged nucleus.
On April 30, 1897, British physicist J.J. Thomson announced his discovery that atoms were made up of smaller components. This finding revolutionized the way scientists thought about the atom and had major ramifications for the field of physics.
What is Dalton's atomic theory?
A theory of chemical combination, first stated by John Dalton in 1803. It involves the following postulates: (1) Elements consist of indivisible small particles (atoms). (2) All atoms of the same element are identical; different elements have different types of atom. (3) Atoms can neither be created nor destroyed.
The theory of Democritus held that everything is composed of "atoms," which are physically, but not geometrically, indivisible; that between atoms, there lies empty space; that atoms are indestructible, and have always been and always will be in motion; that there is an infinite number of atoms and of kinds of atoms,
Explanation:
Answer:
so you can do the maths your self
Explanation:
isotopes are elements with he same proton number but difference in their neutron number
- proton number is also known as the atomic number
- mass number is the sum of the proton number and the neutron number
- mass number = proton number + neutron number
<u>a) Answer: </u>
<em>Number of molecules in 1 mole</em>
<u>Explanation:</u>
a) Whether we take any of the substance among all three of the given substances they will have the same number of molecules in 1 mole of the substance is considered and the value for this will be 
<u>b) Answer: </u>
<em>In the given question </em><em>mass of the substance</em><em> which is </em><em>greatest</em><em> is asked for </em><em>one mole</em><em> and we also know that </em><em>mass of one mole is given by molar mass. </em>
<u>Explanation:</u>
b) It is known that 
is the molar mass for oxygen which is greater than that of hydrogen while fluorine has a molar mass of 
which on comparison shows that, it is the highest amongst all three.
Answer:
This question is incomplete.
Explanation:
This question is incomplete because of the absence of given mass and volume, however, the steps below will help solve the completed question. The molarity (M) of a solution is the number of moles of solute per liter of solvent. The formula is illustrated below;
Molarity = number of moles (n) / volume (in liter or dm³)
To calculate the number of moles of NaC₂H₃O₂, we say
number of moles (n) =
given or measured mass of NaC₂H₃O₂ ÷ molar mass of NaC₂H₃O₂
The volume of the solvent must be in liter (same as dm³). Thus, to convert mL to liter, we divide by 1000
The unit for Molarity is M (Molar concentration), mol/L or mol/dm³
