To what category of elements does an element belong if it is a poor conductor of electricity? (1 point)

Sophie [7]

Answer:

The thumb alone is controlled by nine separate muscles; The hand has been used as a symbol of protection since ancient times; The human hand is different to the hands or paws of other animals, because it has fingers and a thumb that can work together. Each finger has 3 bones and the thumb has two bones

Explanation:

3 0

2 years ago

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When H2(g) reacts with Cl2(g) to form HCl(g) , 185 kJ of energy are evolved for each mole of H2(g) that reacts. Write a balanced

Katyanochek1 [597]

Answer:

H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ

Explanation:

In a chemical reaction, enthalpy of reaction ΔH is a thermodynamic constant that gives information if the reaction is exothermic (Produce heat if reacts) or endothermic (Consume heat if reacts).

In the reaction:

H₂(g) + Cl₂(g) → 2HCl(g) ΔH = -185kJ

As ΔH <0, the reaction is exothermic, that means, <em>produce heat</em>, writing a balanced thermochemical equation:

The enthalpy is as a product beacause an exothermic reaction produces heat.

I hope it helps!

7 0

3 years ago

In the compound cah2 calcium has an oxidation number of 2+ and hydrogen has an oxidation number of

sesenic [268]

The oxidation number of H is -1.

Sum of the oxidation numbers in each element = charge of the complex

CaH₂ has 1 Ca atom and 2H atoms. The charge of the complex is zero. Let’s say Oxidation number of H is "a".

Then,

2a = -2

a = -1

Hence, the oxidation number of Hydrogen atom in CaH₂ is -1

7 0

2 years ago

T/F___ At the eutectic composition, an alloy can solidify at a constant temperature.___ For effective dispersion strengthening,

azamat

Answer:

TRUE
FALSE
TRUE
FALSE
FALSE
TRUE

Explanation:

At the eutectic composition, an alloy can solidify at a constant temperature : TRUE . this is because at eutectic composition the type of reaction that takes place there is invariant reaction in its thermal equilibrium
For effective dispersion strengthening, the dispersed phase should be needle-like, as opposed to round : FALSE. because the rounded shape will not cause a crack.
Intermetallic compounds are usually hard and brittle : TRUE. because Intermetallic compounds prevents dislocation movements and this makes them brittle and hard
For the effective dispersion and strengthening, the dispersed phase should be continuous : FALSE. this is because the dispersed precipitate must be small and not continuous
Stoichiometric intermetallic compounds exist over a range of compositions : FALSE
Faster solidification results in smaller interlamellar spacing : TRUE

4 0

2 years ago

A sample of iron metal is placed in a graduated cylinder. it is noted that 10.4 ml of water is displaced by the iron. the iron i

Pavel [41]

<h3>Answer:</h3>

162.43 g of FeCl₂

<h3>Explanation:</h3>

Step 1: Calculate mass of Fe;

As,

Density = Mass ÷ Volume

Or,

Mass = Density × Volume

Where Volume is the volume of water displaced = 10.4 mL

Putting values,

Mass = 7.86 g.mL⁻¹ × 10.4 mL

Mass = 81.744 g of Fe

Step 2: Calculate amount of FeCl₂;

The balance chemical equation is as follow,

Fe + 2 HCl → FeCl₂ + H₂ ↑

According to this equation,

55.85 g (1 mol) Fe produced = 110.98 g (1 mol) of FeCl₂

So,

81.744 g Fe will produce = X g of FeCl₂

Solving for X,

X = (81.744 g × 110.98 g) ÷ 55.85 g

X = 162.43 g of FeCl₂

7 0

3 years ago