I think the answer is (1) Co. Because the element of Cobalt also has 2 electrons at the outer layer which is the same as Calcium. And the outer layer is an important factor which can affect the property of an element.
Answer:
B. 3+
Explanation:
When Fe²⁺ loses an electron, it becomes an Fe³⁺ ion.
The loss of an electron in an atom makes the atom becomes positively charged. Further losing electrons makes the atom more positive.
For the given ion;
Fe²⁺ if it loses an electron more, it becomes Fe³⁺.
The expression is given as:
Fe²⁺ → Fe³⁺ + e⁻
Answer: C. HNO3 and NaOH
Explanation:
Arrhenius acid produces hydogen ion (H+) when dissolved in water. An example of Arrhenius acid is HNO3.
Arrhenius base produces hydroxyl ion (OH-) when dissolved water. An example of Arrhenius base is NaOH.
<u>Answer:</u> The given quantity is a type of length and is measured i the units of meters.
<u>Explanation:</u>
For the given quantity which is 4.8 meters, the unit is meters ans it the unit used to measure the length of an object.
For example: The height of the building is 150 meters. This statement means that the length of the building from the ground is 150 and it is measured in the units of meters.
Hence, the given quantity is a type of length and is measured i the units of meters.
