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3 years ago

in the symbol 42He, the subscript 2 is the _ for helium and the superscript 4 is the _ for helium.

1 answer:

3 0

The subscript 2 is the atomic number. This tells you the number of protons in the atom. The superscript 4 is the mass number. This tells you the protons + neurons

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What is the mass of 1.24 x 10^23 molecules of N2O2

Scorpion4ik [409]

<h3>Answer:</h3>

12.4 g N₂O₂

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

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table
Moles
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>

[Given] 1.24 × 10²³ molecules N₂O₂

[Solve] grams N₂O₂

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

Avogadro's Number

[PT] Molar Mass of N - 14.01 g/mol

[PT] Molar Mass of O - 16.00 g/mol

Molar Mass of N₂O₂ - 2(14.01) + 2(16.00) = 60.02 g/mol

<u>Step 3: Convert</u>

[DA] Set up: $\displaystyle 1.24 \cdot 10^{23} \ molecules \ N_2O_2(\frac{1 \ mol \ N_2O_2}{6.022 \cdot 10^{23} \ molecules \ N_2O_2})(\frac{60.02 \ g \ N_2O_2}{1 \ mol \ N_2O_2})$
[DA] Divide/Multiply [Cancel out units]: $\displaystyle 12.3588 \ g \ N_2O_2$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

12.3588 g N₂O₂ ≈ 12.4 g N₂O₂

7 0

3 years ago

In a chemical reaction the physical states of each chemical species is denoted by a state symbol. Each state is represented by a

Vedmedyk [2.9K]

Aqueous, it means dissolved in water

3 0

3 years ago

How much Cu-64 (half-life about 12 hours) would remain from a 2 mg sample after 12 hours?

Bogdan [553]

Answer:

i beleive it is A if not here a cookie online cookie also dont forget to wear your mask kiddos

Explanation:

7 0

3 years ago

Read 2 more answers

An ideal gas at 20 degrees centigrade has a volume of 12 liters and a pressure of 15 atmospheres. Its temperature is raised to 3

LiRa [457]

P 15 atm

V₁ = 12x103 m3 -3 3 V₁ = 12x10 m" T₁ = 25°c T= 28815 K

P₁ = 1.52x10 Pa

Now, Finel quantities, T₂ = 35°C = 308.15 °K

V2= 851 = -3 3

Now

by ideal gas equation

P2Y2 T2

= PV, T2

1152 X106 x 12x16 3 x 308115 8,5×103 x 288,15 = Pa

21294×10 Pa

P₂ = 21264 Atm

final

pressure will be

21264 Adm.

Please check the attached file for a brief answer.

Learn more about the temperature at

brainly.com/question/24746268

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3 0

2 years ago

Which observation about methane (ch4) can be explained using the orbital hybridization theory?

MissTica

<span>All 4 C-H bonds are identical.

Hybridisation or hybridization is the idea of blending atomic orbitals into new hybrid orbitals, with various energies, shapes, and so on, than the component atomic orbitals, appropriate for the matching of electrons to make chemical bonds in valence bond theory.
</span>

7 0

3 years ago

in the symbol 42He, the subscript 2 is the _____ for helium and the superscript 4 is the _____ for helium.

in the symbol 42He, the subscript 2 is the _ for helium and the superscript 4 is the _ for helium.