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nydimaria [60]
3 years ago
14

An atom of helium-4 differs from an atom of lithium-7 in that the atom of helium-4 has?

Chemistry
1 answer:
lianna [129]3 years ago
4 0
2.valence electrons while lithium has 5
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Write an equilibrium equation that shows bisulfate acting as a weak acid in water.
NemiM [27]

Answer:

Explanation:

Bisulphate ion is a weak acid as it can form hydronium ion in water .

HSO₄⁻ + H₂O ⇄ SO₄⁻² + H₃O⁺

The equilibrium constant of this reaction is very small , hence bisulphate ion is very weak acid.

4 0
3 years ago
The recommended maintenance dose of penicillin for children is 1.0 mg/kg/hr by injection. Of 10 mL of a 25 mg/mL solution of pen
SOVA2 [1]

This problem is providing us with the recommended maintenance dose of penicillin for children as 1.0 mg/kg/hr by injection. Thus, the delivery rate for a 40-pound child is required, if 10 mL of a 25 mg/mL solution of penicillin is added to a 100-mL bottle of saline. At the end, the result is 8.0 mL/hr:

<h3>Dimensional analysis:</h3>

In chemistry, dimensional analysis allows us to obtain a specific result given relevant information about it. Although a formula is not always provided, one can use the units as a reference for the calculations.

For example, this problem asks for the rate, in mL/hr, at which a child gets this dose, so the first step will be to get the mass of the child in kilograms:

40 lb*\frac{0.4536kg}{1lb}= 18.144kg

Next, we calculate the rate at which the penicillin is delivered to this child:

1.0\frac{mg}{kg*hr} *18.144kg=18.144\frac{mg}{hr}

After that, we calculate the total mass of penicillin that is delivered:

10mL*25\frac{mg}{mL} =250 mg

And get the new concentration once it is diluted to 100 mL:

\frac{250mg}{10mL+100mL}=2.27\frac{mg}{mL}

And finally, we combine the mg/hr with the mg/mL to get the result in mL/hr as required:

18.144\frac{mg}{hr} *\frac{1mL}{2.27mg}\\ \\=8.0\frac{mL}{hr}

Learn more about dimensional analysis: brainly.com/question/10874167

5 0
2 years ago
Compare and contrast reflecting and refracting telescopes. *
Alinara [238K]
A refracting telescope uses convex lenses to gather a large amount of light and focus it onto a small area while a reflecting telescope the mirror instead of an objective lens they are also similar because like the lenses in a refracting telescope the mirror in a reflecting telescope focuses a large amount of light onto a small area.
7 0
3 years ago
Atomic radius increases as you move down a group of elements.
raketka [301]
Yes, the atomic radius increases as you move down a group of elements.  this is true
going down leads to valence electrons that are further away from nucleus -> less electrostatic attraction -> less pull towards nuc. -> greater radius/volume taken
3 0
3 years ago
What is the difference between electron behavior in ionic and covalent bonds?
Flauer [41]

a electron behavior is a subatomic particle whose electric i charge and the other one is a molecule and chemical bond that shares electrons

8 0
3 years ago
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