The water has surface tension
<u>Answer:</u> The atom with 6 protons and 6 neutrons and an atom with 6 protons and 7 neutrons are the isotopes of same element.
<u>Explanation:</u>
Isotopes are defined as the chemical species that belong to the same element but differ in their mass number.
This also means that the chemical species have same number of protons and electrons but different number of neutrons.
Atomic number is defined as the number of protons or electrons that are present in a neutral atom.
Atomic number = number of protons = number of electrons
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
From the given options:
The elements having same number of protons will be the isotopes of same element.
Hence, the atom with 6 protons and 6 neutrons and an atom with 6 protons and 7 neutrons are the isotopes of same element.
We could (a) stir faster and (b) warm the mixture.
<em>Stirring faster</em> moves freshly-dissolved sugar away from the solid and allows new water molecules to contact with the surface,
<em>Warming the mixture</em> gives the water molecules more kinetic energy, so their collisions with the surface of the sugar will be more effective in removing the sugar molecules.
Answer:
249.94ppm
Explanation:
Given parameters:
Mass of Pb(NO₃)₂ = 0.025g
Mass of water = 100g
Unknown:
Concentration of solution in ppm = ?
Solution:
Concentration in parts per million gives the amount of solute found in a million units of the solution. They are desirable for expressing very small amount of solutes in a large solution. For example, the level of arsenic in the soil.
Concentration in ppm = 
A solution is made up of solute and solvent. The solvent here is water.
mass of solution = mass of solute + mass of solvent = 0.025 + 100 = 100.025g
Concentration in ppm = 
= 249.94ppm
Answer:
Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.
