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1 year ago

Number of

Chemistry

1 answer:

babymother [125]1 year ago

8 0

Answer:

A) 20

B) 40

C) Ca

D) 10

E) 9

F) F

Explanation:

The MASS NUMBER is the number of protons + the number of neutrons.

The ATOMIC NUMBER is the number of protons.

You can take the MASS NUMBER - ATOMIC NUMBER = NUMBER OF NEUTRONS.

Each element is unique and distinguished by the NUMBER OF PROTONS = ATOMIC NUMBER, ie...the number of protons in its nucleus. You can find the element's name and symbol on the Periodic Table.

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In your own words, explain why the Linnaean system has changed over time pls help

sergiy2304 [10]

Classification systems are mental models that we create to make sorting things simpler and more efficient. We make compromises to emphasize certain details and hide others based on their perceived relevance to achieving the outcomes we seek. Even if the original model was nearly perfect, you should expect the inputs provided and outcomes desired to change as time goes by.

In time, we usually find that we have over-simplified by ignoring important details. Mental models such as classification systems should evolve over time. This enables them to more accurately reflect reality and lead to the outcomes we seek.

You can only find the details you seek by observing the right layer of abstraction.

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1 year ago

Does a radio have electrical and mechanical energy

soldi70 [24.7K]

Answer:

Electrical

Explanation:

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2 years ago

We can also use the equation for enthalpy change for physical phase changes. Consider the phase change H2O(l) → H2O(g). Calculat

VLD [36.1K]

Answer: The value of enthalpy of the given reaction is 44.000 kJ/mol , that is energy is supplied to water to change into water vapors

Explanation:

$H_2O(l)\rightarrow H_2O(g),\Delta H_{rxn}=?$

Enthalpy of formation of water in liquid state, $\Delta H_{f,H_2O(l)}=-285.820 kJ/mol$

Enthalpy of formation of water in gaseous state, $\Delta H_{f,H_2O(g)}=-241.820 kJ/mol$

$\Delta H_{rxn}=\sum \Delta H_f \text{of products}-\sum \Delta H_f \text{of reactants}$

$\Delta H_{rxn}=(-241.820 kJ/mol)-(-285.820 kJ/mol)=44.000 kJ/mol$

The value of enthalpy of the given reaction is 44.000 kJ/mol, that is energy is supplied to water to change into water vapors.

6 0

2 years ago

Read 2 more answers

Calculate the solubility of copper(II) hydroxide, Cu(OH)2, in g/L

Oduvanchick [21]

Answer:

Ksp = [ Cu+² ] [ OH-] ²

molar mass Cu(oH )2 ==> M= 63.546 (1) + 16 (2) + 1 (2) = 97.546 g/mol

Ksp = [ Cu+² ] [ OH-] ²

Ksp [ cu (OH)2 ] = 2.2 × 10-²⁰

|__________|___Cu+² __|_2OH-____|

|Initial concentration(M)|___0__|_0______|

|Change in concentration(M)|_+S |__+2S__|

|Equilibrium concentration(M)|_S _|2S___|

Ksp = [ Cu+² ] [ OH-] ²

2.2 ×10-²⁰ = (S)(2S)²= 4S³

$s = \sqrt[3]{ \frac{2.2 \times {10}^{ - 20} }{4} } = 1.8 \times {10}^{ - 7}$

S = 1.8 × 10-⁷ M

The molar solubility of Cu(OH)2 is 1.8 × 10-⁷ M

Solubility of Cu (OH)2 =

$Cu (OH)2 = \frac{1.8 \times {10}^{ - 7} mol \:Cu (OH)2 }{1L} \times \frac{97.546 \: g \: Cu (OH)2}{1 \: mol \: Cu (OH)2} \\ = 1.75428 \times 10 ^{ - 5}$

<h3>Solubility of Cu (OH)2 = 1.75428 × 10 -⁵ g/ L</h3>

I hope I helped you^_^

8 0

2 years ago

4. Write down the differentiate between a. Atom and molecules

andre [41]

Answer:

Atoms are single neutral particles. Molecules are neutral particles made of two or more atoms bonded together.

Explanation:

Atom refers to the smallest constituent unit of a chemical element. Molecules refer to a group of two or more atoms that are held together due to chemical bonds.

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2 years ago

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