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3 years ago

Beryllium (Be): 1sC2sD, what's C and D?

Chemistry

2 answers:

katen-ka-za [31]3 years ago

7 0

C=2
D=2
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answer

Tatiana [17]3 years ago

6 0

Answer:

C is equal to 2 and D is equal to 2.

Explanation:

Here C and D represents number of electrons in 1s and 2s orbitals.

Be has 4 electrons. Now, in order write electronic configuration of an atom, electron filling should be started from orbital with lowest energy.

Energy order of orbital with increasing energy: 1s< 2s< 2p< 3s< 3p< 4s< 3d....

So, filling of electron should start from 1s orbital then 2s, 2p, 3s, 3p and so on.

Each orbital can have maximum of 2 electrons.

So electronic configuration of Be is: $1s^{2}2s^{2}$

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Using logarithms, you determined the A)Solubility B)Temperatures C)ph

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Answer:

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Explanation:

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3 years ago

In a 28 g serving of cheese curls there are 247mg of sodium. How much sodium is in a 12.5 ounce bag

Marina86 [1]

Answer:

There should be about 3136.9mg of Na in a 12.5oz bag of cheese curls.when rounding if not rounded it would be 3126.04082143mg

Explanation:

12.5oz=354.4g

354.4/28=12.7

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3 years ago

How is an average mass different from a weighted mass

romanna [79]

In an average mass, each entry has equal weight. In a weighted average, we multiply each entry by a number representing its relative importance.

Assume that your class consists of 15 girls and 5 boys. Each girl has a mass of 54 kg, and each boy has a mass of 62 kg.

Average mass = (girl + boy)/2 = (54 kg + 62 kg)/2 = 58 kg

Weighted average (Method 1)

Use the numbers of each gender (15 girls + 5 boys) ,

Weighted average = (15×54 kg + 5×62 kg)/20 = (810 kg + 310 kg)/20

= 1120 kg/20 = 56 kg.

If you put all the students on one giant balance, their total mass would be

1120 kg and the average mass of a student would be 56 kg.

Weighted average (Method 2)

Use the relative percentages of each gender (75 % girls and 25 % boys).

Weighted average = 0.75×54 kg + 0.25×62 kg = 40.5 kg + 15.5 kg = 56 kg

Each girl contributes 40.5 kg and each boy contributes 15.5 kg to the weighted average mass of a student.

6 0

3 years ago

A metal crystallizes in a body-centered cubic unit cell. The radius of one atom = 2.30 x 10 -8 cm. The density of the metal is 0

maw [93]

Answer:

25.41 g/mol is molar mass of metal.

Explanation:

Number of atom in BCC unit cell = Z = 2

Density of metal = $0.867 g/cm^3$

Edge length of cubic unit cell= a = ?

Radius of the atom of metal = r = $2.30\times 10^{-8} cm$

$a=2\times r=2\times 2.30\times 10^{-8} cm=4.60\times 10^{-8} cm$

Atomic mass of metal =M

Formula used :

$\rho=\frac{Z\times M}{N_{A}\times a^{3}}$

where,

$\rho$ = density

Z = number of atom in unit cell

M = atomic mass

$(N_{A})$ = Avogadro's number

a = edge length of unit cell

On substituting all the given values , we will get the value of 'a'.

$0.867 g/cm^3=\frac{2\times M}{6.022\times 10^{23} mol^{-1}\times (4.60\times 10^{-8} cm)^{3}}$

$M = 25.41 g/mol$

25.41 g/mol is molar mass of metal.

6 0

3 years ago

if you have the chemical formula of a substance what can you figure out about its properties? explain, use the compound water h2

mezya [45]

You can find the makeup of the substance, such as water having two hydrogen atoms and one oxygen.

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3 years ago