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3 years ago

Which metalloid has three valence electrons? 1. Lithium 2. boron 3. silicon 4. aluminum 5. arsenic

Chemistry

2 answers:

iren [92.7K]3 years ago

5 0

Answer:

boron

Explanation:

kobusy [5.1K]3 years ago

5 0

Answer:

Explanation:

Edgenuity

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What is the charge of this atom? <br> 65 protons <br> 60 electrons <br><br> A)-5<br> B)+5<br> C)0

Pani-rosa [81]

Answer:

B. +5

Explanation:

4 0

3 years ago

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Identify which sets of quantum numbers are valid for an electron. Note that each set is ordered (n,l,ml,ms).

Fynjy0 [20]

Answer:

The answer to your question is:

Explanation:

Quantum numbers have the numbers

n = from 1 to 7

l = s = 0 p = 1 d = 2 f= 3

m = ± l

s = ±1/2

Group of answer choice.

A) 2, -1. 1, -1/2 The option is incorrect "l" could not be negative

B) 2, 1, 0 , 1/2 The option is posible

C) 3, 2, 1, -1 This option is incorrect "s" can not value -1

D) 4, 3, 2, 1/2 This option is correct

E) 4, 3, -4, 1/2 This option is incorrect "m2 can not value -4

F) 1, 1, 0, 1/2 This option is incorrect, the second number is not posible

G) 1, 1, 0, -1/2 This option is incorrect the second number could not be 1.

H) 3, 0, 0, 1/2 This option is incorrect "l" can not value 0

I) 0, 2, 0, 1/2 This option is incorrect, n can not value 0

J) 3, 2, 2, 1/2 This option is correct

K) 1, 2, 0, -1/2 This option is incorrect "l" can not value 2.

3 0

3 years ago

at standard pressure, what is the temperature at which a saturated solution of NH4Cl has a concentration of 60g NH4CL/100 g H2O

Nataliya [291]

Answer: Temperature = T, unknown

Saturated Solution, NH4Cl concentration = 60g/100g H2O = 0.6g NH4Cl/g H2O

Assume density of H2O = 1 g/ml

m = 0.6g NH4Cl/g H2O / 1 g/ml

m = 0.6g NH4Cl/ml

See the table of saturated solutions and identify the temperature at which the concentration of NH4Cl is 60g/100g H2O.

Explanation: The line on the graph on reference table G indicates a saturated solution of NH4CL as a concentration of 60. g NH4 Cl/100. g H2O

5 0

2 years ago

1 Na2CO3(aq) + 1 CaCl2(aq) → 1 CaCO3(s) + 2 NaCl(aq) 4. Use the balanced chemical equation from the last question to solve this

LenKa [72]

<h3>Answer:</h3>

0.6 g NaCl

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Balanced] Na₂CO₃ (aq) + CaCl₂ (aq) → CaCO₃ (s) + 2NaCl (aq)

[Given] 0.5 g Na₂CO₃ reacted with excess CaCl₂

<u>Step 2: Identify Conversions</u>

[RxN] Na₂CO₃ → 2NaCl

Molar Mass of Na - 22.99 g/mol

Molar Mass of C - 12.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of Na₂CO₃ - 2(22.99) + 12.01 + 3(16.00) = 105.99 g/mol

Molar Mass of NaCl - 22.99 + 35.45 = 58.44 g/mol

<u>Step 3: Stoichiometry</u>

Set up: $\displaystyle 0.5 \ g \ Na_2CO_3(\frac{1 \ mol \ Na_2CO_3}{105.99 \ g \ Na_2CO_3})(\frac{2 \ mol \ NaCl}{1 \ mol \ Na_2CO_3})(\frac{58.44 \ g \ NaCl}{1 \ mol \ NaCl})$
Multiply/Divide: $\displaystyle 0.551373 \ g \ NaCl$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 1 sig fig.</em>

0.551373 g NaCl ≈ 0.6 g NaCl

5 0

3 years ago

Which element does X represent in the following expression: 2512X?

pogonyaev

<span>I bet this is the notation used in nuclear reactions. The superscript represents the mass number while the subscript represents the atomic number of the element X. So, we find the element with an atomic number of 12. That would be Magnesium or Mg.</span>

8 0

3 years ago

Read 2 more answers