Which sentence is a scientific statement?

A.
There is a substance around us that cannot be detected.
B.
Kids should go to school for 12 years.
C.
Experimentation is the best way to obtain knowledge.
D.
Unicorns once existed on Earth.
E.
There are no living things on the Moon.

Answer:

wind is the correct answer

Answer:

thunderstorms

Explanation:

Answer:

Equation:

p + 8p = 63

9p = 63

Divide both sides by 9:

p = 7

The parakeet weights 7 ounces.

Weight of fish:

The fish weights 8 times as much as the parakeet, or 8 * 7 = 56 ounces

The fish weights 56 ounces.

Explanation:

Answer:

Explanation:

A decomposition reaction occurs when one reactant breaks down into two or more products. This can be represented by the general equation: AB → A + B. Examples of decomposition reactions include the breakdown of hydrogen peroxide to water and oxygen, and the breakdown of water to hydrogen and oxygen.

Answer:

Covalent bond

Explanation: Hydrogen and Oxygen are both non-metals, with a low difference in electronegativity. They will share electrons.

Answer:

a. bond angles c. bond length

Explanation:

Models are abstractions of the real world. They are used to present either real or hypothetical situations either visually, graphically or through mathematical expressions.

Answer:

(D) greater than the energy stored in the bonds of the products.

Explanation:

Exothermic reaction refer to those reactions in which energy is released to the surrounding, unlike endothermic reactions where energy is absorbed from the surroundings.

In exothermic reactions, the change in energy; ΔH less than zero. That is, they are negative.

ΔH = H (products) - H (reactants)

For ΔH to have a negative value, it means the energy of reactant must be greater than the energy of products.

This means the correct option is;

(D) greater than the energy stored in the bonds of the products.

In an exothermic reaction the energy of the reactants bonds has been higher than the energy of the product bonds. Thus, option D is correct.

The exothermic reaction has been given as the chemical reaction in which there has been the liberation of energy by the reactants in the process of formation of products.

The energy change in the reaction has been a negative value. In the process of product formation, the energy of the system has been conserved. It stated that the energy of the reactant has been equivalent to the energy of the product and the liberated energy.

With the product being consisted of less energy, the energy stored by the chemical bonds in the reactants has been higher than the energy stored by the product. Thus, option D is correct.

For more information about the exothermic reaction, refer to the link:

https://brainly.com/question/14969584

Answer:

Ore

hope this helps

thanks for the points

Answer: mass of electron is

9.10938356 × 10^-31 kilograms

Explanation:

Answer:

D

Explanation:

it doesn't matter how many protons k has all the answers have electron with the positive charge when is negative the question is trying to distract you D is the only one that would use the electrons sign correctly

Answer:

See the answer below

Explanation:

When magnesium is heated in air, the element combines with oxygen to form a compound known as magnesium oxide according to the following equation:

    [tex]2Mg(s) + O_2 (g)--> 2MgO (s)[/tex]

Hence, the product formed - a combination of magnesium and the oxygen component of air - is heavier than the original magnesium ribbon.

On the other hand, potassium manganate (7) is heated in air and decompose to form potassium manganate (6), manganate oxide, and oxygen gas according to the following equation:

    [tex]2KMnO_4 --> K_2MnO_4 + MnO_2 + O_2[/tex]

Hence, the final product formed is lighter than the original product because oxygen gas has been evolved.

Answer:

During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide. However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off.

Explanation:

During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide.

The equation for the reaction is given below:

2Mg(s) + O2(g) ---> 2Mg0

The molar mass of the magnesium metal is 24.0 g while the mass of the magnesium oxide is 40.0 g. The total mass of the metal before heating is 24 × 2. + 32 = 48.0 g. The total mass after heating = 48 + 32 = 80.0 g. Therefore, there is an increase in mass.

However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off. The equation for the reaction is given below;

2KMnO4(s) ----> K2MnO4(s) + MnO2(s) + O2(g)

With the evolution of oxygen gas, there's a loss in mass of potassium manganate (vii). Molar mass of KMnO4 is 158.0 g while the mass of K2MnO4 is 197.0 g and that of MnO2 is 87.0 g. The total mass on the right hand side is 2 × 158 = 316.0 g. The total mass on the left-hand side with the exception of the gas evolved is 284.0 g. Therefore, there is a loss in mass.

The balanced equation :

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

Given

The following reaction(combustion of Propanol) :

C₃H₇OH+O₂⇒ CO₂ +H₂O​

Required

Balanced equation

Solution

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:  

• 1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.  

• 2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product  

• 3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

1. Give coefficient

C₃H₇OH+aO₂⇒ bCO₂ +cH₂O​

2. Make an equation

C, left=3, right=b⇒b=3

H, left=8, right=2c⇒2c=8⇒c=4

O, left=1+2a, right=2b+c⇒1+2a=2b+c⇒1+2a=2.3+4⇒1+2a=10⇒2a=9⇒a=9/2

The equation becomes

C₃H₇OH+9/2O₂⇒ 3CO₂ +4H₂O x 2

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

Answer:

Fluorine-18

Explanation:

An isotope is an element with different amounts of neutrons.  The element itself will not change.

Answer:

a

Explanation:

it is the concentration of the hydrogen ion, more hydrogen ion more acidic less hydrogen ion less acidic and alkaline.

Answer:

The percent natural abundance is 27.95% for the heavier isotope (86.901 amu)

Explanation:

The atomic mass of Rubidium (Rb) is 85.468.

To find the percent natural abundance, first we need to use the following equation:

84.912x + 86.901(1-x) = 85.468

x represents the percent natural abundance, in basic decimal form

In order to find x, we will use the distributive property, combine like terms and then move the constant to the other side to get x.

We are first finding the percent natural abundance of the first isotope to make this easier for us.

84.912x + 86.901(1-x) = 85.468

-> 84.912x + 86.901- 86.901x = 85.468

-> 86.901 - 1.989x  = 85.458      (like terms were combined)

-> Subtract both sides by 86.901

-> Divide both sides by-1.989x

x = 0.720462544

Now turn this into a percent by multiplying by 100.

--> 72.05% for the first isotope (the one that contains 84.912 amu)

To find the natural abundance of the other isotope (the denser, heavier isotope), you could just subtract 72.05 from 100 to save time, but the usually desired way (the way that your teacher would probably want you to do) is down below:

We plug this decimal for the x-value into the parentheses from earlier:

(1 -x) ---> ( 1 - 0.720462544 ) = 0.279537456

Now we just need to convert this to a percent by multiplying by 100

0.279537456 * 100 = 27.95% of the heavier isotope (86.901 amu)

Answer:

Ae4

Explanation:

which virtually showed the reaction between group 4 element and group 7 element

Answer:

C4H2O6

Explanation:

Answer:

See explanation

Explanation:

1) The formula of the compound is Fe2(SO4)3. There are two ion atoms in any formula unit as we can see here. Three sulphate ions are attached to iron. Each iron ion carries a +3 charge as we saw in the formula. The total positive charge in each formula unit is +6.

Changing a subscript in a correctly written chemical formula changes the formula so that it no longer represents the compound it previously represented. Hence FeSO4 is a different compound from Fe2(SO4)3.

in one molecule we have one oxygen atom so we will have 4 oxygen atoms in 4 molecules

Explanation:

On a hot day, the speed at which we perceived the smell of the perfume will be much faster due to the increase in kinetic energy of the perfume molecules.

Based on the kinetic molecular theory of gases, the average motion of particles increases as their thermal energy increases. On a hot day, the heat causes an increase in the average kinetic energy of the particles and the perfume molecules moves faster.

On a cold day, the molecules are slower and the rate at which we perceive the perfume smell is very slow. The particles will diffuse less faster and this is due to the low average kinetic energy they possess.

Answer:

When zinc metal is reacted with hydrochloric acid, hydrogen gas is released and an aqueous solution of zinc chloride is produced. ... It is important that all of the zinc used be reacted and that large excess amounts of hydrochloric acid not be used.

Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. Whereas, hydrated and aqueous forms of zinc chloride are prepared by treating zinc with hydrochloric acid. Zinc metal could either be in the form of zinc sulfide or zinc oxide

Have a nice Day , Hope this helped you I would appreciate it if you could mark my answer brainliest

Merry Christmas

Answer: Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. ... Zinc metal could either be in the form of zinc sulfide or zinc oxide. ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(g) There are impurities present in zinc chloride samples due to hydrolysis.

got this from goo.gle

Hope this helps.......... Stay safe and have a Merry Christmas!!!!! :D

Answer:

ok thats cool good luck with that and always remember God is there for you :)

Answer:

yeah

Explanation:

in every situation we should trust God

The equilibrium constant K : 0.089

Given

Reaction

H₂O(g)+Cl₂O(g)⇔2HClO(g)

[H2O]=0.077M,[Cl2O]=0.077M,[HClO]=0.023M

Required

the equilibrium constant

Solution

The equilibrium constant or Kc is the value of the concentration product in the equilibrium state of the substance in the right segment divided by the product of the substance in the left section, each of which has a reaction coefficient raised  

[tex]\tt K=\dfrac{[HClO]^2}{[H_2O][Cl_2O]}\\\\K=\dfrac{0.023^2}{0.077\times 0.077}\\\\K=0.08922[/tex]

Answer:

D Earth's hot interior

Explanation:

The internal heat engine of the earth is the energy source that powers plate movement.

The sun drives the surface process and provides energy for the external heat engine

Therefore, the heat is used to melt rocks and set up convection currents that drives plate movements.

Answer:

Ways to reduce friction are by using oil, rollers from roller blades or other stuff that has a roller in or on it, wax, and grease.

Explanation:

Oil can reduce friction because it is used as a lubricant to reduce friction so moving surfaces slide smoothly over one another the same thing with wax and grease. The rollers are because they reduce friction by reducing contact between moving surfaces.

Answer:

C. democritusm John dalton, JJ Thomason, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

The correct order of the scientists in order of their work related to the

structure of an atom from earliest to most recent include Democritus, John

Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

Democritus was regarded as one of the earliest scientist who first proposed

atomic theory around 460 BC which was then modified and used by others

such as John Dalton, JJ Thomson, Ernest Rutherford and Neils Bohr.

The most recent of them all was Erwin Schrodinger which was  the wave

equation for electron movements in the 20th century.

Read more on https://brainly.com/question/20339664

Answer:

Sulfur

Explanation:

it has 16 proton and 2- charges

Answer:

C = 9460 Kj

Explanation:

Given data:

Mass of copper = 2kg

Latent heat of vaporization = 4730 Kj/Kg

Energy required to vaporize 2kg copper = ?

Solution:

Equation

Q= mLvap

by putting values,

Q= 2kg ×  4730 Kj/Kg

Q = 9460 Kj

Answer:

B) 101,025

Explanation:

1000g * 0.449 J/g Celsius * 225 Celsius = 101,025

I got 225C from 250C - 25C