Why are bubbles and color changes not always chemical change?

Answer:

Explanation:

Tough question.

The answer is very dependent on the temperature of the water. At 0o C, less than 5 grams is soluble in water.

The curve increases as the temperature increases. At 80oC about 35 grams  is soluble in water 100 mL of water.  So Ba(OH)2 is very soluble at higher temperatures.

Maybe the question can be resolved just a little better at room temperature. The solubility is still less than 5 grams / 100 mL. That makes it slightly soluble or more soluble than other things.

So to answer the question, you need to specify the temperature. I would say it is, but be prepared to defend your answer.

Answer:

4500 cent

Explanation:

From the question, we were told that

a fence 80 meters long requires 30 nails per meter.

1 metre fence = 30 nails

Then 80 meters long= ( 30 × 80)

= 2400 nails

Which means a fence 80 meters long will require 2400 nails in total.

We need to find the cost in dollars for the nails to build a fence 80 meters long.

We know that 40 nails per box will cost 75 cents per box.

(2400 nails/40 nail per box)= 60 box

Then 60 box will be needed to complete the fence.

the cost in dollars for the nails to build a fence 80 meters long= (60 box × 75 cent per box)=4500 cent

Answer:

B - Covalent bonds

Explanation:

Covalent bonds are a class of chemical bonds where valence electrons are shared between two atoms, typically two nonmetals. The formation of a covalent bond allows the nonmetals to obey the octet rule and thus become more stable.

Answer:

D. solid candle wax near the flame melts as the candle burns.

Answer:

Part D, melting is a product of heating

Explanation:

Answer:

See Explanation

Explanation:

Let us consider the first two reactions, the initial concentration of CO was held constant and the concentration of Hbn was doubled.

2.68 * 10^-3/1.34 * 10^-3 = 6.24 * 10^-4/3.12 * 10^-4

2^1 = 2^1

The rate of reaction is first order with respect to Hbn

Let us consider the third and fourth reactions. The concentration of Hbn is held constant and that of CO was tripled.

1.5 * 10^-3/5 * 10^-4 = 1.872 * 10^-3/6.24 * 10^-4

3^1 = 3^1

The reaction is also first order with respect to CO

b) The overall order of reaction is 1 + 1=2

c) The rate equation is;

Rate = k [CO] [Hbn]

d) 3.12 * 10^-4 = k [5 * 10^-4] [1.34 * 10^-3]

k = 3.12 * 10^-4  /[5 * 10^-4] [1.34 * 10^-3]

k = 3.12 * 10^-4/6.7 * 10^-7

k = 4.7 * 10^2 mmol-1 L s-1

e) The reaction occurs in one step because;

1) The rate law agrees with the experimental data.

2) The sum of the order of reaction of each specie in the rate law gives the overall order of reaction.

Answer:

B) nitrogen

the Earth's atmosphere is mostly nitrogen

Answer:

Investigating how carbon dioxide levels impact ocean pH

Explanation:

I hope this helps! :)

Answer:

divide the moles by gram to get molar mass

use calculator and get yo ans

Salt added : 14.5 g

Given

17% salt solution

71 ml water

Required

salt needed

Solution

%mass = (mass solute : mass solution) x 100%

71 ml water = 71 g water(density = 1 g/ml)

mass solute = x

[tex]\tt 17\%=\dfrac{x}{x+71}\times 100\%\\\\0.17(x+71)=x\\\\0.17x+12.07=x\\\\0.83x=12.07\\\\x=14.5[/tex]

Answer:

i believe it is b as well

Explanation:

Answer:

this is a multiple choice question where are the answers

Explanation:

Answer:

zinc metal (ZN) is an element

Answer:

3 releases energy

Explanation:

An electron in an energy level has a definite amount of energy associated with it at that level.

Electrons can undergo transitions from one level to another. However, when the electron changes its state, it must absorb or emit the exact amount of energy which will bring it from the initial to the final state.

When the electron is excited, it moves from the ground state to an excited state, it must absorb energy. On returning from an excited state to a lower level or the ground state, energy is emitted, giving rise to a line in the spectrum.

Answer: 3 because it releases energy

Answer:

A

Explanation:

The study of a chemical is called chemistry.

The correct answer is A

Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.

The radioactive of the Ra is option A that is:-

[tex]RA^{226}_{88}----->Rn^{222}_{86} +He^4_2[/tex].

During the decomposition, the element is breakdown into the neutron, proton, and electron.

Hence, the correct answer is A.

For more information, refer to the link:-

https://brainly.com/question/14698383

Answer:

There are 0.00047212 wig in 3.0099 dumps.

Explanation:

In this problem, we need to convert 3.0099 dumps to wigs.

6375.23 dumps = 1 wig (given)

1 dump = (1/6375.23) wig

To convert 3.0099 dumps to wigs, multiply 3.0099 by (1/6375.23).

3.0099 dumps = [tex]\dfrac{1}{6375.23}\cdot3.0099[/tex]

= 0.00047 wig

Hence, there are 0.00047212 wig in 3.0099 dumps.

Answer:

The answer is p⁴.

Explanation:

You have to apply Indices Law :

[tex] {a}^{m} \times {a}^{n} ⇒ {a}^{m + n} [/tex]

For this question :

[tex] {p}^{3} \times {p}^{1} [/tex]

[tex] = {p}^{(3 + 1)} [/tex]

[tex] = {p}^{4} [/tex]

A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal. P₄ + 4NaOH + 2H₂O → 2PH₃ + 2Na₂HPO₃.

A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal.

A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process.

To know more about balanced chemical equation, visit;

https://brainly.com/question/14015590

#SPJ4

Answer: 1.51355 mol.

Explanation:

Answer:

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

hope this helps ^^

Answer:

22g of  2

C

O

2

have  3.011×1023

3.011

×

10

23

  2

C

O

2

molecules.

Explanation:

Hope this helps! ^^