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4 years ago

Elements are composed of

Chemistry

2 answers:

Sladkaya [172]4 years ago

4 0

It is a hope it helps

skad [1K]4 years ago

3 0

The correct answer is B, 'the same type of atom'. By definition, an element is a single type of atom. They are the most basic forms of matter, and so they cannot be more than one kind of atom, and they also cannot be a compound, since compounds are made up of multiple atoms.

Hope this helps!

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PLEASE HELP! Class is almost ending, I don't want to repeat.

nikklg [1K]

ANSWERS:

1. $2KClO_{3}$ ⇒ 2KCl + $3O_{2}$

2. $H_{2} C_{2} O_{4} + 2NaOH$ ⇒ $Na_{2} C_{2} O_{4} + 2 H_{2} O$

3. $2 C_{10} H_{22} + 31O_{2}$ ⇒ $20C O_{2} + 22 H_{2} O$

4. $4 H_{2} + Fe_{3} O_{4}$ ⇒ $3Fe +4 H_{2} O$

5. $4P + 5 O_{2}$ ⇒ $2 P_{2} O_{5}$

I have attached my work for 1-3. I would like to see if you can get 4 and 5 on your own. but, if you are struggling/copnfused please let me know in the comments! :)

6 0

4 years ago

The chemical force for which of the following ions is directed into the cell? The chemical force for which of the following ions

Over [174]

Answer:

Both sodium and calcium.

Explanation:

The membrane potential is maintained inside and outside of the cell due to the unequal distribution of the different ions. This membrane potential difference is important for the generation of action potential.

The resting membrane potential is around +30 mV. This is due to the presence of potassium ions. The sodium and calcium ions must enter in the cell to change this membrane potential and generates the action potential in the body.

Thus, the correct answer is option (3).

5 0

3 years ago

What is the pH of a solution with a 1.50x10-9 M hydroxide ion concentration?

dimaraw [331]

Answer: 5.18

Explanation:

Mathematically, pOH is expressed as

pH = -log(OH-)

where OH-is the concentration of hydroxide ion

So, pOH calculations are as follows

pOH = -log(1.50x10-9 M)

pOH = -(-8.82)

pOH = 8.82 [the two minus signs cancelled out]

Since pOH = 8.82; apply the formula

pH + pOH = 14 to get pH of the solution

Hence, pH + pOH = 14

pH + 8.82 = 14

pH = 14 - 8.82

pH = 5.18

Thus, the pH of a solution with a 1.50x10-9 M hydroxide ion concentration is 5.18 (slightly acidic)

4 0

4 years ago

20 POINTS!<br><br> what would be an example of an everyday household acid and base?

Elza [17]

Answer:

Baking Soda, Vinegar, Ammonia

Explanation:

4 0

3 years ago

Read 2 more answers

Multiple choice-- please help!

kvasek [131]

The rate law for the reaction : r=k.[A]²

<h3>Further explanation</h3>

Given

Reaction

A ⟶ B + C

Required

The rate law

Solution

The rate law is a chemical equation that shows the relationship between reaction rate and the concentration / pressure of the reactants

For the second-order reaction it can be:

1. the square of the concentration of one reactant.

$\tt r=k[A]^2$

2. the product of the concentrations of two reactants.

$\tt r=k[A][B]$

And the reaction should be(for second order) :

2A ⟶ B + C

Thus, for reaction above (reactant consumption rate) :

$\tt r=-\dfrac{\Delta A}{2\Delta t}=k[A]^2$

6 0

3 years ago