Las nubes el agua y el Hielo son lo mismo?

An atom emits a photon of wavelength 1.08 meters. What is the energy change occurring in the atom due to this emission? (Planck'

kati45 [8]

The answer is 1.84×10^(-25).

4 0

3 years ago

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The atomic number tells us how many __ or __ an element contains.

CaHeK987 [17]

Answer:-
Electrons or Protons

Explanation:-
Atomic number (Z) is defined as:
>>“The total number of protons in the nucleus of an atom is called atomic number”. All atoms of an element have the same number of protons and electrons.
>>“The total number of protons in the nucleus or electrons revolving around the nucleus of an atom”.
Example:
For instance, Hydrogen has the Atomic number(Z) 1.
Helium has the atomic number 2.
Oxygen has the atomic number 8.
| Note | Atomic number is represented by “Z”. And some ppl don’t consider the 2nd definition it’s upto u to do both or the standard one.

5 0

3 years ago

A scientist measures the standard enthalpy change for the following reaction to be -17.2 kJ : Ca(OH)2(aq) 2 HCl(aq)CaCl2(s)

elixir [45]

Answer: $\Delta H^{0}=-173.72$ kJ/mol

Explanation: Enthalpy Change is the amount of energy in a reaction - absorption or release - at a constant pressure. So, Standard Enthalpy of Formation is how much energy is necessary to form a substance.

The standard enthalpy of formation of HCl is calculated as:

$\Delta ^{0}=\Sigma H_{products}-\Sigma H_{reactants}$

$Ca(OH)_{2}_{(aq)}+2HCl_{(aq)}$ → $CaCl_{2}_{(s)}+2H_{2}O_{(l)}$

Standard Enthalpy of formation for the other compounds are:

Calcium Hydroxide: $\Delta H^{0}=$ -1002.82 kJ/mol

Calcium chloride: $\Delta H^{0}=$ -795.8 kJ/mol

Water: $\Delta H^{0}=$ -285.83 kJ/mol

Enthalpy is given per mol, which means we have to multiply by the mols in the balanced equation.

Calculating:

$-17.2=[-795.8+2(285.85)]-[-1002.82+2\Delta H]$

$-17.2=-1367.46+1002.82-2\Delta H$

$2\Delta H=17.2-364.64$

$\Delta H=-173.72$

So, the standard enthalpy of formation of HCl is -173.72 kJ/mol

8 0

3 years ago

write the symbols for the ions that form when potassium and iodine react to form the ionic compound potassium iodide.

Bingel [31]

I believe it isK+ + I-=KI

3 0

3 years ago

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How many atoms are found in 3.45g of CO2?

USPshnik [31]

Answer: The number of carbon and oxygen atoms in the given amount of carbon dioxide is $4.72\times 10^{22}$ and $9.44\times 10^{22}$ respectively

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of carbon dioxide gas = 3.45 g

Molar mass of carbon dioxide gas = 44 g/mol

Putting values in above equation, we get:

$\text{Moles of carbon dioxide gas}=\frac{3.45g}{44g/mol}=0.0784mol$

1 mole of carbon dioxide gas contains 1 mole of carbon and 2 moles of oxygen atoms.

According to mole concept:

1 mole of a compound contains $6.022\time 10^{23}$ number of molecules

So, 0.0784 moles of carbon dioxide gas will contain $1\times 0.0784\times 6.022\times 10^{23}=4.72\times 10^{22}$ number of carbon atoms and $2\times 0.0784\times 6.022\times 10^{23}=9.44\times 10^{22}$ number of oxygen atoms

Hence, the number of carbon and oxygen atoms in the given amount of carbon dioxide is $4.72\times 10^{22}$ and $9.44\times 10^{22}$ respectively

3 0

3 years ago