Tom tells Greta that his father, an astronomer, is planning a scientific experiment to study another galaxy. Using a powerful telescope, Tom's father will record data of shifts in light patterns and track their different sources every 30 seconds. He will later study the data. Greta says that this is not an experiment. Which of these reasons supports Greta's statement?


It is not performed in a lab.


There are too many variables.


It does not have a control group.


It uses only theoretical predictions.

Answer:

1.62x10⁻¹² M

Explanation:

HClO₃ is a strong acid, meaning that a 6.2x10⁻³ M solution has a molar concentration of H⁺ of 6.2x10⁻³.

With the above information in mind, we can calculate the pH of the solution:

Now we can calculate the pOH of the solution, using the pH:

Finally we calculate [OH⁻], using the definition of pOH:

Answer:

Explanation:

ABC Powder: sprays a very fine chemical powder. This acts to blanket the fire and suffocate it. Class A, B, C fires

Carbon dioxide: extinguishes CO2. By doing so, it removes oxygen from the fire, effectively suffocating it of oxygen. Class B fires

Foam: spray a type of foam that expands when it hits the air and blankets the fire. This prevents the vapors from rising off the liquid to feed the fire, thus starving it of fuel. Class A and B

Water: releases microscopic water molecules that fight the fire on a variety of levels. the level of oxygen in the air is decreased, which helps to suffocate the fire. Class: most all

also, your fire classes:

Class A: freely burning, combustible solid materials such as wood or paper

Class B: flammable liquid or gas

Class C: energized electrical fire (energized electrical source serves as the ignitor of a class A or B fire – if electrical source is removed, it is no longer a class C fire)

Class D: metallic fire (titanium, zirconium, magnesium, sodium)

Class K: cooking fires – animal or vegetable oils or fats

Answer:

They all have a certain amount of protons electrons and neutrons.

Answer:

A

Explanation:

Each DNA sequence that contains instructions to make a protein is known as a gene. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans.

Answer:

Na2CO3 + CaCl2 → CaCO3 + 2 NaCl

Explanation:

A double displacement reaction is a type of metathesis reaction in which two reactants exchange ions to form two new compounds. Double displacement reactions usually involve reacting two soluble salts in aqueous solution resulting in the formation of two products: a soluble salt and an insoluble salt that is produced as a precipitate.

If the reaction of two soluble compounds does not produce a precipitate, the reaction does not result in the formation of a product as basically, all the ions are mixed together in the reaction vessel.

From the given reactions above:

1. 3 KBr + AlPO4 → K3PO4 + AlBr3

The reaction does not proceed to product formation as the two products are all soluble salts.

2. Na2CO3 + CaCl2 → CaCO3 + 2 NaCl

The reaction occurs as one of the products, CaCO3 is insoluble as is produced as a precipitate.

3. NH4OH + KCl → KOH + NH4Cl

The reaction does nott occuras the products are all soluble in water.

4. ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2

The reaction does not occur as the products are all soluble in water.

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

We have

[tex]volume = \frac{24}{8} = 3 \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

Ali is incorrect.

Explanation:

Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.

She could say the weather is rainy, because that is short term, but not the climate.

Answer:Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.

Explanation:

Answer:

If the star has smaller mass than the Sun, it can fuse hydrogen into helium for at least a trillion years. The larger a star, the shorter its life because it fuses hydrogen into helium much more quickly. A star whose mass is more than 20 Suns will run out of hydrogen in only a few hundred million years.

Answer:

0.525 M

Explanation:

As the problem deals with a dilution process, we can use the following formula:

Where subscript 1 stands for initial concentration and volume, while 2 stands for the final conditions. Meaning that in this case:

We input the data given by the problem:

And solve for C₂:

Answer:

1

because a dwarf star will seemlarge because of the in ability of any human being to see d sun

Answer:

The correct answer is -

if the potential energy of reactants is less than the potential energy then it is an endothermic reaction and if the potential energy of reactants is more than the products it is an exothermic reaction.

Explanation:

The potential energy graph represents the energy change in a reaction as it progresses. In the initial part of the reaction, the energy shows are the energy of reactants that takes part in the reaction, and in the later phase, the energy has represented the energy of products of the reaction.

To find the reaction if it is endothermic or exothermic one can see if the potential energy is increased or decrease with the progress of the reaction. if the reaction is increasing in energy with the progress then it is endothermic and exothermic in less energy.

Answer:

Streak

Explanation:

Hope it Help

Thanks me later

So, litmus paper is a qualitative tool for assessing the acidity or basicity of a substance (usually a solution). In general, blue litmus turns red in the presence of an acid, and red litmus turns blue in the presence of a base. They can't really tell you much more than that.

The solutions that are most likely acids are those that turn blue litmus red and do not evoke a color change in red litmus. A solution that turns red litmus blue or does not evoke a color change in blue litmus is likely not an acid. Using these criteria, solutions 4 and 7 are most likely acids since they both turn blue litmus red (and they cause no color change in red litmus).

The correct answer choice would thus be D.

Answer:

molecules will speed up

Explanation:

Answer:

The elements can be classified as metals, nonmetals, or metalloids. ... Elements are further classified into metals, non-metals, and metalloids based on their properties, ... when they undergo chemical reactions They normally do not accept ... Most metal oxides are basic oxides and dissolve in water to form .

Explanation:

Answer:

The answer is a

Explanation:because yes

Answer: The answer is B.

Explanation: The rocks falling off is caused by gravity. Other options don't include effects of gravity; Therefore, B is correct.

Answer:

1. Practice healthy habits with kids in your life. ...

2. Engage in your school's efforts to encourage healthy practices. ...

3. Learn more about the decisions local officials are making that impact your environment. ...

4. Give back healthy options to your community.

Explanation:

Answer:

CH2

Explanation:

The empirical formula is the lowest ratio form of a compound. You can divide both C and H by 3 to get to CH2.

Answer:

MgBr2

Explanation:

(Mg^2+) + (Br^1-)

For every Mg we need 2 Br to balance out the compound.

Since magnesium has two outer electrons, it can donate one electron each to two bromine atoms having seven outer electrons in order for each of the atoms to have a complete octet.

Since the octet rule states that a stable atom must have eight electrons in its outermost shell, it follows that magnesium could give out two of its outermost electrons to two bromine atoms.

When that happens, each bromine atom which previously had seven electrons now have eight electrons, satisfying the octet rule. The correct formula of the compound is MgBr2.

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Answer:

Not sure sorry :(

Explanation:

Answer:

=KSO4+Na2(NO3)2

Explanation:

the answer is true using this chemical equation balancer

Answer:

K8S4O16 or K8(SO4)4 depending on if the SO4 is supposed to represent sulfate or not

Explanation:

Find the molar mass of K2SO4 first:

2K + S + 4O ≈ 174 g/mol

Divide the goal molar mass of 696 by the molar mass of the empirical formula:

696 / 174 = 4

This means you need to multiply everything in the empirical formula by 4:

K2SO4 --> K8S4O16 or K8(SO4)4 depending on if the SO4 is for sulfate or not

K₈S₄O₁₆  is the molecular formula for a compound with the empirical formula K₂SO₄ and a molecular mass of 696 g​.

Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.

Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.

In this case molar mass of K₂SO₄  that is 696 is divided by empirical formula mass which is 174.25 g which gives 4 , subscripts of  K₂SO₄  is multiplied by 4 to give K₈S₄O₁₆ .

Thus, the molecular formula of compound is K₈S₄O₁₆.

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Answer:

a.Provide the body which shape and protection.

Explanation:

Bones usually gives us shape as well as protects our innner organs.

so if it helps don't forget to like and Mark me

Answer:

[tex]\color{Blue}\huge\boxed{Question} [/tex]

[tex]\color{Blue}\huge\boxed{Answer} [/tex]

Answer: structural

Explanation:

When metals and non metals combine in fixed proportion then a chemical compound is formed. Structural formula shows an element symbol for each atom and a line for each bond between atoms. The correct option is option A.

Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.

Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral.

Out of given structural is a 3D representation of any chemical formula, in which symbol of each element is shown .Along with symbol line for each bond between atoms is also shown.

Therefore, the correct option is option A.

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Answer:

soil

Explanation: