Answer:
creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes.
Explanation:
Nuclear energy produces radioactive waste
A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years.
To create the Lewis structure we need to take into account the octet rule: atoms tend to gain, lose or share electrons to complete their valence shell with 8 electrons.
C belongs to Group 4A in the periodic table so it has 4 valence electrons. It needs to share 4 pairs of electrons to complete the octet.
F belongs to Group 7A in the periodic table so it has 7 valence electrons. Each F needs to share 1 pair of electrons to complete the octet.
As a consequence, in CF₄, C will form a single bond with each F and all the octets will be complete.
Answer:
C) Modernization of humans
The correct answer is 96.80 grams
Explanation:
The density of a substance shows the total mass the substance contains in 1 mL or 1 cm3 as density is calculated by using the formula D= M (mass) / V (volume). This implies, Iron contains 7.87 grams per milliliter. Moreover, this value and formula can be used to calculate the mass or volume of any other sample. The process to calculate the mass of an iron sample with a volume of 12.3 mL is shown below.
D = M ÷ V
7.87 mL = x ÷ 12.3 mL - x represents the missing value. Now find the value of x by solving the equation
x = 7.87 · 12.3
x = 96.80
This means a sample of 12.3 mL contains a mass of 96.80 grams. Also, you can know this value is correct because if you divide the mass by the value the density is the same (96.80 grams ÷ 12.3 mL = 7.87 g/mL)