If an atom the atomic number 10 and the mass number 12, how many VALENCE electrons does it have?

posledela

The tractor would have the most kinetic energy :D

3 0

1 year ago

The maps above show a front as it moves east across the United States. Which of these describes the weather change that can be e

kobusy [5.1K]

It’s D,the cold will bring cooler temperatures.....:)

4 0

2 years ago

Explain how the mass of a single atom in an element (in amu), the mass of one mole of that element, and Avogadro’s number are re

Eva8 [605]

Answer: For 1 mole of a single atom it is equal to its molar mass. And a single atom, 1 mole is equal to the Avogadro's Number.

Explanation: The relationship can be expressed through the following:

1 mole = molar mass of an atom/ compound

1 atom x 1 mole / 6.022x10^23 atoms

4 0

2 years ago

Use the data given below to construct a Born-Haber cycle to determine the heat of formation of KCl. Δ H°(kJ) K(s) → K(g) 89 K(g)

AURORKA [14]

Explanation:

The net equation will be as follows.

$K(s) + Cl_{2}(g) \rightarrow KCl(s)$

So, we are required to find $\Delta H_{formation}$ for this reaction.

Therefore, steps involved for the above process are as follows.

Step 1: Convert K from solid state to gaseous state

$K(s) \rightarrow K(g)$ , $\Delta H_{1}$ = 89 kJ

Step 2: Ionization of gaseous K

$K(g) \rightarrow K^{+}(g) + e^{-}$ , $H_{2}$ = 418 KJ

Step 3: Dissociation of $Cl_{2}$ gas into chlorine atom .

$\frac{1}{2} Cl_{2}(g) \rightarrow Cl(g)$ , $\Delta H_{3} = \frac{244}{2}$ = 122 KJ

Step 4: Iozination of chlorine atom.

$Cl(g) + e^{-} \rightarro Cl^{-}(g)$ , $H_{4}$ = -349 KJ

Step 5: Add $K^{+}$ ion and $Cl^{-}$ ion formed above to get KCl .

$K^{+}(g) + Cl^{-}(g) \rightarrow KCl(s)$ , $H_{5}$ = -717 KJ

Now, using Born-Haber cycle, value of enthalpy of the formation is calculated as follows.

$\Delta H_{f} = \DeltaH_{1} + \Delta H_{2} + \Delta H_{3} + \Delta H_{4} + \Delta H_{5}$

= 89 + 418 + 122 - 349 - 717

= - 437 KJ/mol

Thus, we can conclude that the heat of formation of KCl is - 437 KJ/mol.

5 0

3 years ago

Electrons surround the , of an atom in various energy levels called

nasty-shy [4]

surrounds the nucleus of an atom in various energy levels called orbitals.

Explanation:

Electrons surrounds the nucleus of an atom in various energy levels called orbitals.

According to the Bohr's model of an atom, the extra nuclear space is made up of electrons in specific spherical orbits called shells or energy levels.

The region of a maximum probability of where an electron is located is sometimes referred to as an electron cloud or orbital.
Electrons move round the nucleus in certain permissible orbits.
An electron in an energy level posses a definite amount of energy associated with it at that level.
Electrons moves through the energy levels by gaining or losing energy.

Learn more:

Bohr brainly.com/question/4986277

#learnwithBrainly

7 0

2 years ago