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2 years ago

Help anyone? :) please

Chemistry

1 answer:

Elanso [62]2 years ago

8 0

Answer:

6. protons, mass number from the atomic number

7. Li= ,

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What are reasons standardizing conditions in which chemist describe matter?

ExtremeBDS [4]

Matter is the basic unit of every thing in the world, whether living or nonliving. So, it is logical to set definitions and postulates because these could pave way to other complexities of science. It is the foundation of science. That is why theories and laws are formulated for matter such as: Kinetic Theory of Matter, Dalton's Atomic Model, Newton's Law of Motion, Conservation Laws and many more.

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2 years ago

What is the correct name for the cyclic alkane shown on the right?

Soloha48 [4]

Answer: C

Explanation:

4 0

3 years ago

Read 2 more answers

A chemist adds 215.0mL of a 6.0x10^−5/mmolL mercury(II) iodide HgI2 solution to a reaction flask. Calculate the micromoles of me

Snezhnost [94]

The micromoles of mercury(II) iodide : 0.013 μ moles

<h3>Further explanation</h3>

Given

215.0mL of a 6.0x10⁻⁵mmol/L HgI₂

Required

micromoles of HgI₂

Solution

Molarity(M) = moles of solute per liters of solution

Can be formulated :

M = n : V

n = moles

V = volume of solution

V = 215 mL = 0.215 L

so moles of solution :

n = M x V

n = 6.10 mmol/L x 0.215 L

n = 1.312 . 10⁻⁵ mmol

mmol = 10³ micromol

so 1.312 mmol = 1.312.10⁻⁵ x 10³ = 0.01312 micromoles ⇒ 2 sif fig = 0.013 μ moles

6 0

2 years ago

Give the Unabbreviated electron configuration for barium

Shalnov [3]

Answer:

Ba: 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰5p⁶ 6s²

Step-by-step explanation:

Step 1. Locate barium in the Periodic Table.

It's in Period 6, Group 2: Element 56 (highlighted blue in the Periodic Table below).

Step 2. Add 54 electrons to the energy levels

You add then in the order shown in the diagram below.

The complete electron configuration is:

Ba: 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰5p⁶ 6s²

n = 2 + 8 + 8 + 18 + 18 + 2 = 56

8 0

3 years ago

How many molecules are in 0.55 moles of Cu(NO3)2?

xeze [42]

<h3>Answer:</h3>

3.3 × 10²³ molecules Cu(NO₃)₂

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

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

0.55 mol Cu(NO₃)₂

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

Avogadro's Number

<u>Step 3: Convert</u>

[DA] Set up: $\displaystyle 0.55 \ mol \ Cu(NO_3)_2(\frac{6.022 \cdot 10^{23} \ molecules \ Cu(NO_3)_2}{1 \ mol \ Cu(NO_3)_2})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 3.3121 \cdot 10^{23} \ molecules \ Cu(NO_3)_2$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 2 sig figs.</em>

3.3121 × 10²³ molecules Cu(NO₃)₂ ≈ 3.3 × 10²³ molecules Cu(NO₃)₂

4 0

3 years ago