Adults have stem cells because they are needed to repair certain tissues in the body such as in the muscles, bone marrow, skin, teeth, heart, and liver, to name a few. Thus, they can develop into many different cell types and function to replace older and damaged tissues.

3 0

3 years ago

Read 2 more answers

A buret is filled with 0.1517 M naoh A 25.0 mL portion of an unknown acid and two drops of indicator are added to an Erlenmeyer

antiseptic1488 [7]

Answer:

molarity of acid =0.0132 M

Explanation:

We are considering that the unknown acid is monoprotic. Let the acid is HA.

The reaction between NaOH and acid will be:

$NaOH+HA--->NaA+H_{2}O$

Thus one mole of acid will react with one mole of base.

The moles of base reacted = molarity of NaOH X volume of NaOH

The volume of NaOH used = Final burette reading - Initial reading

Volume of NaOH used = 22.50-0.55= 21.95 mL

Moles of NaOH = 0.1517X21.95=3.33 mmole

The moles of acid reacted = 3.33 mmole

The molarity of acid will be = $\frac{mmole}{volumne(mL)}=\frac{0.33}{25}=0.0132M$

4 0

3 years ago

Please helpppppp I be thankful

grigory [225]

Valence électrons don’t define which group You are in so you can cross those choices out.
A would be incorrect because element 1 has 1 valence electron while element 2 has 2 valence electrons.
D would be correct because both elements have two valence electrons.
Also, pls don’t hate if I am wrong!

8 0

3 years ago