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:
a. Minimum 1.70 V
b. There is no maximum.
Explanation:
We can solve this question by remembering that the cell potential is given by the formula
ε⁰ cell = ε⁰ reduction - ε⁰ oxidation
Now the problem states the cell must provide at least 0.9 V and that the reduction potential of the oxidized species 0.80 V, thus
ε⁰ reduction - ε⁰ oxidation ≥ ε⁰ cell
Since ε⁰ oxidation is by definition the negative of ε⁰ reduction , we have
ε⁰ reduction - ( 0.80 V ) ≥ 0.90 V
⇒ ε⁰ reduction ≥ 1.70 V
Therefore,
(a) The minimum standard reduction potential is 1.70 V
(b) There is no maximum standard reduction potential since it is stated in the question that we want to have a cell that provides at leat 0.9 V
Answer:
58mL
Explanation:
Given parameters:
Density of water = 1g/mL
Mass of object = 58g
Unknown:
The volume the object must have to be able to float in water = ?
Solution:
To solve this problem, we know that the object must have density value equal to that of water or less than that of water to be able to float.
We then set its density to that of water;
Density = 
Volume = 
So;
Volume = 
= 58mL
Answer:
A metalloid is a substance that has both the qualities of a metal and a non metal. Metals conduct electricity and have a high melting point.The element described does not conduct electricity until temperatures are reduced therefore it is not a metal. The fact that conduction occurs when temperatures are reduced means that it is not a non metal because non metals do not conduct electricity at all. Therefore the element is a metaloid because it exhibits some properties of a metal and others of a non mental.
Explanation:
Answer:
Because the density of water is one
