I think verterbrates have a back bone others do not. I only THINK so.
Answer:
D
Explanation:
The simple answer is the electrons in the outermost energy level.
Hydrogen has 1 electron in the outermost energy level.
Magnesium has 2 so this tells you that magnesium has a charge of 2
Oxygen has 6 oxygen has a charge of - 2
Fluorine has 7
For most elements, the electrons in the most outer ring determine the valence of the element.
Notice that the non metals work differently than the metals. Mg may have a charge of 2 and that is the number of electrons in the valence right.
Oxygen is a non metal it has a charge of - 2. It gets 6 electrons by subtracting the number of its charge from 8.
Answer:
There are 64 fish, 8 ducks and 4 turtles.
Explanation:
From the question, there can be from 2 to 99 fish in the pond. However, there cannot be fractions in the number of fish, ducks or turtles. Hence, the number of fish must have both of a perfect square and perfect cube. The perfect squares from 2 to 99 are 4, 9, 16, 25, 36, 49, 64 and 81. The perfect cubes from 2 to 99 are 8, 27 and 64. Since only 64 fits both criteria, the number of fish is 64. The number of ducks is the square root of number of fish, which is the square root of 64. The square root of 64 can be either positive 8 or negative 8. However, there cannot be negative numbers, so there are 8 ducks in total. The number of turtles is the cube root of the number of fish, which is the cube root of 64 and it is 4.