Answer:
Experiment plays many roles in science. One of its important roles is to test theories and to provide the basis for scientific knowledge. It can also call for a new theory, either by showing that an accepted theory is incorrect, or by exhibiting a new phenomenon that is in need of explanation.
Explanation:
The answer is Thermal Energy :)
Answer:
d. white blood cells
Explanation:
It is the white blood cells that have the least tendency to cross the blood- brain barrier.
Blood- brain barrier is psychological barrier and restricts substances that circulate into the blood from crossing over the central nervous system.
Water, glucose as well as sodium ions can easily cross the barrier. As these are good for body supply energy to the brain.
Answer:
D
Explanation:
heterogeneous mixture you can see the different substances that go into it.
homogeneous mixture you can't see the difference, the mixture looks like one substance.
I will present a simple reaction so we can do this conversion:
2H₂ + O₂ → 2H₂O
We will assume we have 32 g of O₂ and we want to find the amount of water, assuming this reaction goes to completion. We must first convert the initial mass to moles, which we do using the molar mass in units of g/mol. The molar mass of O₂ is 32 g/mol.
32 g O₂ ÷ 32 g/mol = 1 mole O₂.
Now that we have moles of oxygen, we use the molar coefficients to find the ratio of water molecules to oxygen molecules. We can see there are 2 moles of water for every 1 mole of oxygen.
1 moles O₂ x (2 mol H₂O/ 1 mol O₂) = 2 moles H₂O
Now that we have the moles of water, we can convert this amount into grams using the molar mass of water, which is 18 g/mol.
2 moles H₂O x 18 g/mol = 36 g H₂O
Now we have successfully converted the mass of one molecule to the mass of another.
