Hey what is your question? i can help! :)
The correct answer is B. An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.
Explanation:
Electrons are negatively charged particles found in atoms. These different from protons and neutrons are not located in the nucleus of the atom but orbit it. Additionally, electrons do not orbit the nucleus following a linear pattern but they have a wave-like behavior which means they move in a three-dimensional space or area known as electron orbital in which they can be found most of the time, this space of area is determined depending on energy, momentum, and other factors. Thus, an electron orbital is "a three-dimensional space where an electron can be found 90% of the time".
Answer:HIV attacks a specific type of immune system cell in the body. It's known as the CD4 helper cell or T cell. When HIV destroys this cell, it becomes harder for the body to fight off other infections. When HIV is left untreated, even a minor infection such as a cold can be much more severe.
Explanation:
The correct answer is b.
The child is reaching for a toy which is not visible to him (hidden under a cloth), therefore, the child has a mental representation of the object in his/her mind. This action means that the child acknowledges that the objects continue to exist even when he/she can not hear or see them. This thought process is called object permanence and it is an ability acquired between the 4th and 7th month of a child's development.