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3 years ago

Which of the following elements is a metal in the periodic table

Chemistry

1 answer:

OverLord2011 [107]3 years ago

8 0

Answer:

12 My Magnesium

13 Al Aluminum

19 K Potassium

20 Ca Calcium

Explanation:

I think

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1. Nitrogen, oxygen, and fluorine atoms all seem pretty similar, at first. How many valence electrons does an atom of each have?

matrenka [14]

Nitrogen is 5 valence electrons
oxygen is 6 valence electrons
fluorine is 7 electrons

6 0

3 years ago

The free energy change for the following reaction at 25 °C, when [Cr3+] = 1.32×10-3 M and [Fe3+] = 1.14 M, is 131 kJ: Cr3+(1.32×

larisa [96]

Answer:

E°cell = - 1.3575 V

This reaction is spontaneous in the reverse direction

Explanation:

The given cell reaction:

Cr³⁺(1.32 × 10⁻³ M) + Fe²⁺(aq) → Cr²⁺(aq) + Fe³⁺(1.14 M)

The given Gibbs free energy: ΔG = 131 kJ = 131 × 10³ J (∵ 1 kJ = 10³ J)

As we know,

ΔG = - n F E°cell

Here, n - the number of moles of electrons transferred = 1

F - Faraday constant = 96500

E°cell - cell potential = ?

$\therefore E^{\circ }_{cell} = -\frac{\Delta G}{n \: F} = -\frac{131\times 10^{3}\, J}{1\, mol\times96500 \, C.mol^{-1}}$

$\Rightarrow E^{\circ }_{cell} = -1.3575\, V$

For a given chemical reaction if-

1. ΔG = negative and E°cell = positive

⇒ The reaction is spontaneous and proceeds spontaneously in the forward direction.

2. ΔG = positive and E°cell = negative

⇒ The reaction is non-spontaneous and proceeds spontaneously in the reverse direction.

Since, for this chemical reaction: 

Cr³⁺(1.32 × 10⁻³ M) + Fe²⁺(aq) → Cr²⁺(aq) + Fe³⁺(1.14 M)

ΔG = + 131 × 10³ J ⇒ positive

and, E°cell = - 1.3575 V ⇒ negative

Therefore, this reaction is spontaneous in the reverse direction.

6 0

3 years ago

Given the following reaction: 2D(g) + 3E(g) + F(g) \longrightarrow⟶ 2G(g) + H(g) When the concentration of D is decreasing by 0.

Zepler [3.9K]

Answer:

Rate of reaction = -d[D] / 2dt = -d[E]/ 3dt = -d[F]/dt = d[G]/2dt = d[H]/dt

The concentration of H is increasing, half as fast as D decreases: 0.05 mol L–1.s–1

E decreseas 3/2 as fast as G increases = 0.30 M/s

Explanation:

Rate of reaction = -d[D] / 2dt = -d[E]/ 3dt = -d[F]/dt = d[G]/2dt = d[H]/dt

When the concentration of D is decreasing by 0.10 M/s, how fast is the concentration of H increasing:

Given data = d[D]/dt = 0.10 M/s

-d[D] / 2dt = d[H]/dt

d[H]/dt = 0.05 M/s

The concentration of H is increasing, half as fast as D decreases: 0.05 mol L–1.s–1

When the concentration of G is increasing by 0.20 M/s, how fast is the concentration of E decreasing:

d[G] / 2dt = -d[H]/3dt

E decreseas 3/2 as fast as G increases = 0.30 M/s

5 0

3 years ago

What do the little numbers (subscripts) next to the lower right of each letter mean in the C₂H₄O₂?

nata0808 [166]

Answer:

It represents the number of atoms of that particular element present in the compound. In C₂H₄O₂ there are 2 Carbon atoms, 4 Hydrogen atoms and 2 Oxygen atoms.

3 0

2 years ago

The circles in the diagrams below represent energy levels in an atom, and the arrows show electron (blue dot) transitions from o

Hoochie [10]

Ranking of the atom from highest to lowest is as follows:
Highest
Arrow = from outer edge to center
2nd Highest
Arrow = second closest ring to the outer edge to center
3rd Highest
Arrow = middle circle to center
Lowest
Arrow = outer edge to middle circle

6 0

3 years ago

Which of the following elements is a metal in the periodic table​

Which of the following elements is a metal in the periodic table