An early model of the atom was developed in 1913 by Danish scientist Niels Bohr (1885–1962). The Bohr model shows the atom as a central nucleus containing protons and neutrons with the electrons in circular orbitals at specific distances from the nucleus . These orbits form electron shells or energy levels, which are a way of visualizing the number of electrons in the various shells. These energy levels are designated by a number and the symbol "n." For example, 1n represents the first energy level located closest to the nucleus.
Answer:
The answer is D.
Explanation:
Intermolecular force are negligible
When the distance between molecules decrease,
the attraction or repulsion become greater
Answer:
acid rain
Explanation:
When sulfur dioxide combines with water and air, it forms sulfuric acid, which is the main component of acid rain. Acid rain can: cause deforestation.
Answer:
0.292 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density of an object is simply defined as the mass of the object per unit volume of the object. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the density of the object as follow:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density = mass / volume
Density = 28.1 / 96.2
Density of object = 0.292 g/mL
Thus the density of the object is 0.292 g/mL
Answer:
5200 ppm
Explanation:
As per the definition, parts per million of a contaminant is a measure of the amount of mass of contaminant present per million amount of the solution. It is denoted by ppm.
Given in the question,
Water = 250 ml = 250 g
Lead = 1.30 g
So,
ppm of Lead = 
= 
= 5200 ppm
So, as calculated above, there is 5200 ppm of lead present in 250 ml of water.
