Answer: it's part of the immune system that focuses on specific foreign particles. Rather than generically attack any antigens, T cells circulate until they encounter their specific antigen. As such, T cells play a critical part in immunity to foreign substances !
Explanation:
The question is incomplete, the complete question is;
Which statement describes a difference between electromagnetic and mechanical waves?
A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.
B. Electromagnetic waves cannot move particles, but mechanical waves can.
C. Electromagnetic waves do not require a medium, but mechanical waves do.
D. Mechanical waves do not transfer energy, but electromagnetic waves do.
Answer:
Electromagnetic waves do not require a medium, but mechanical waves do.
Explanation:
A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.
A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.
Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.
I believe the correct response is A. A solution with a pH close to 14 is considered a strong base.
It will stay at a constant temperature while it is boiling which is 212°F
Answer:
3 mol Cl₂/2 mol AlCl₃ (three over two)
Step-by-step explanation:
Start with the balanced equation"
2Al + 3Cl₂⟶ 2AlCl₃
The steps in the calculation are
mass of AlCl₃ ⟶ moles of AlCl₃⟶ moles of Cl₂ ⟶ mass of Cl₂
The critical step is the <em>conversion of moles</em>.
You multiply the moles of AlCl₃ by a <em>conversion factor</em> to get moles of Al:
Moles of AlCl₃ × conversion factor = moles of Al.
The conversion factor is <em>the molar ratio</em>, and it uses the coefficients of the formulas in the balanced equation.
It is either (2 mol AlCl₃/3 mol Cl₂) or (3 mol Cl₂/2 mol AlCl₃).
You choose the one that has the desired units of the answer in the numerator.
We choose the second option, because it has the correct units.
For example,

Notice how the units "mol AlCl₃" cancel and the correct units appear in the answer.
If we had used the other conversion factor, we would have gotten the wrong units.