1: True
2: True
3: False
4: False
(Question 2 might not be true, not sure)
Answer:
1.30464 grams of glucose was present in 100.0 mL of final solution.
Explanation:
Moles of glucose =
Volume of the solution = 100 mL = 0.1 L (1 mL = 0.001 L)
Molarity of the solution =
A 30.0 mL sample of above glucose solution was diluted to 0.500 L:
Molarity of the solution before dilution =
Volume of the solution taken =
Molarity of the solution after dilution =
Volume of the solution after dilution=
Mass glucose are in 100.0 mL of the 0.07248 mol/L glucose solution:
Volume of solution = 100.0 mL = 0.1 L
Moles of glucose =
Mass of 0.007248 moles of glucose :
0.007248 mol × 180 g/mol = 1.30464 grams
1.30464 grams of glucose was present in 100.0 mL of final solution.
Answer:
They have properties of both metals and nonmetals
Explanation:
- Elements in the periodic table may be divided into Metals, non-metals, and metalloids.
- Metals are the elements that react by losing electrons to form stable positively charged ions known as cations. Examples are group 1, 2, and 3 elements together with transition elements.
- Non-metals are those elements that react by gaining electrons to form stable negatively charged ions called anions. Examples include oxygen, carbon, sulfur, etc.
- Metalloids, on the other hand, are elements that have both metallic and non-metallic properties.
- Metalloids occur between metals and non-metals in the periodic table. Examples include Boron and silicon among others.
Answer: The energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.
Explanation:
Given: n = 2
The relation between energy and orbit of an atom is as follows.
Substitute the values into above formula as follows.
The negative sign indicates that energy is being released.
Thus, we can conclude that the energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.