Answer:
Explanation:
7A 0.2
7B cork
7C Yes because the lighter it is the more likely it will float
7D Density is one of the fundamental scientific principles of life. It can describe any everyday object. Despite its significance, students often struggle to understand what it really is. Density is a measurement of how much space or volume is packed in an object or substance.
8 property means a characteristic or trait that you can use to describe matter by observation, measurement, or combination.
Molarity can be defined as the number of moles of solute in 1 L solution.
Molarity of Na₂SO₄ solution - 0.200 M
this means there are 0.200 moles in 1 L solution
Molar mass of Na₂SO₄ - 142 g/mol
therefore mass of Na₂SO₄ in 1.00 L - 0.200 mol x 142 g/mol = 28.4 g
a mass of 28.4 g of Na₂SO₄ is present in 1.00 L
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
...
Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV
