What’s this called

Please ASAP

Explanation:

The lack of a control group

What is the DNA strand? You have not named it.

Answer:

The correct option is;

CO₂

Explanation:

The given information are;

The number of molecules in the substance = 1.3 × 10²⁵

The mass of the substance = 968 g

Therefore, we have;

The number of molecules in one mole of a substance = 6.02 × 10²³

The number of moles present = (1.3 × 10²⁵)/(6.02 × 10²³) ≈ 21.595 moles

Therefore, 968 g = 21.595 moles

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

Therefore the mass of one mole of the substance is closely related to the mass of one mole of CO₂ which is 44.01 g/mol.  

The correct option is CO₂

The number of molecules in one mole of a substance should be = 6.02 × 10²³

And,

The number of moles present is

= (1.3 × 10²⁵)/(6.02 × 10²³)

≈ 21.595 moles

Now

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

So,  the mass of one mole of the substance is closely related to the mass of one mole of CO₂ i.e.  44.01 g/mol.  

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Answer:

=0.00123

Explanation:

Look at the attachments below

Hope this helps (:

Answer:

0.00123

Explanation:

Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).

The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.

In 1.23 x 10^-3 move the decimal to the left 1 place to get:

0.123

two places to get:

0.0123

and a third place to get:

0.00123

The final answer is 0.00123

Answer:

Oxgen- cannot be separated

Water - chemical change

Gold - cannot be separated

Carbon Dioxide - chemical change

Carbon​ - cannot be separated

Explanation:

A pure substance, which can either be an element or a compound, contains only one type of such element or compound. In opposition to a mixture, pure substances cannot be separated by physical means.

- Elements as a pure substance cannot be separated because it contains only one type of atom. However, compounds contain two or more types of atoms, and hence, can only be separated into its individual atoms via chemical means.

In this question, oxygen (O2), Gold (Au) and carbon (C) are all elements and hence cannot be separated. Carbon dioxide (CO2) and water (H2O) are compounds because they contain two different atoms respectively, hence, can be separated into individual atoms.

Answer:

3.05x10²³ (3 sig. fig.)

Explanation:

Propane (C₃H₈) is a colorless alkane gas with three carbons and eight hydrogen atoms. In 2.23 grams of propane, there are 3.05 x 10²³ carbon atoms present.

The number of atoms or the particles being the smallest units is estimated by the product of the number of moles and Avogadro's number.

The Avogadro's number (Na) is used to determine the number of particles that have been present in a mole of a substance. A mole of a substance is said to have 6.022 × 10²³ ions, atoms, electrons, molecules, etc.

Moles of propane are calculated as,

Moles = mass ÷ molar mass

= 2.23 ÷ 440.094

= 0.05057

Now, the number of particles is calculated as,

Number = moles × Avogadro's number

= 0.05057 × 6.022 × 10²³

= 3.05 x 10²³

Therefore, 3.05 x 10²³ carbon atoms are present in 2.23 grams of propane.

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Answer:

Explanation:

option A is correct

Answer:

162.7miles/hr

Explanation:

Given parameters:

Distance covered by the train  = 813.5miles

Time taken  = 5hours

Unknown:

Speed of the train  = ?

Solution:

Speed is a physical quantity.

It is mathematically expressed as;

      Speed  = [tex]\frac{distance}{time}[/tex]

So, input parameters and solve;

   Speed  = [tex]\frac{813.5}{5}[/tex]  = 162.7miles/hr

Answer:

This strange green slime is a colonization of fungi caused by the humidity of the bathrooms, which to be eradicated requires a non-specific antimicrobial such as sodium hypochlorite that generates an osmotic imbalance producing a fungicidal effect.

Explanation:

The fungi that appear in the form of slime at the microscopic level have many forms of colonization, by adding coconut milk it was assumed that this would generate an environment not suitable for their metabolism and reproduction but this did not happen, therefore they continued their reproduction.

Answer:

Explain?

Explanation:

Answer: One of the most striking features of many protist species is the presence of some type of locomotory organelle, easily visible under a light microscope. A few forms can move by gliding or floating, although the vast majority move by means of “whips” or small “hairs” known as flagella or cilia, respectively. (Those organelles give their names to informal groups—flagellates and ciliates—of protists.) A lesser number of protists employ pseudopodia. Those same organelles may be used in feeding as well.

Explanation:

Ah yes.

The atomic radius is basically the distance between the nucleus of the atom and the outermost electron in the farthest orbital of the atom. The more bigger the atomic radius , the less powerful is the force that holds together the nucleus and its electrons.

Answer:

A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.

Explanation:

A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.

Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemical formula CCl4.

Answer:

100°

Explanation:

For a boiling point is it always 100°

Answer:

explanations below

Explanation:

The alkaline earth metals are the 6 chemical elements that can be found in group two of the periodic table. These elements have a lot of properties in common, in the sense that they are generally shiny, reactive at standard temperature and pressure and they are also silvery-white. The elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)

These metals have two electrons at their orbits, which can be easily lost to form cations (with charge +2, and an oxidation state of +2)  

Below are some of their details

Name: Beryllium  

Number of Protons/Electrons: 4  

Number of Neutrons: 5  

Name: Magnesium  

Number of Protons/Electrons: 12  

Number of Neutrons: 12  

Name: Calcium  

Number of Protons/Electrons: 20  

Number of Neutrons: 20  

Name: Strontium  

Number of Protons/Electrons: 38  

Number of Neutrons: 50  

Name: Barium  

Number of Protons/Electrons: 56  

Number of Neutrons: 81  

Name: Radium  

Number of Protons/Electrons: 88  

Number of Neutrons: 138  

Answer:

20

Explanation:

Answer:

B: The colors of light emitted from heated atoms had very specific energies.

Explanation:

dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)

Answer:

b

Explanation:

Answer:

15 atoms total

Explanation:

2 Al atoms + 3 O atoms = 5 Al2O3 atoms

5 Al2O3 atoms * 3 = 15

another way to do it is:

2 Al atoms * 3 = 6 Al atoms

3 O atoms * 3 = 9 O atoms

6+9 =15 atoms total

The number of atoms in the given 3Al₂O₃ is 15 atoms.

Atoms are the smallest unit of every matter. It contains charged particles present inside the atoms. They are electrons, protons, and neutrons. Atoms are of four types, description, isotopes, radioactive, and ions.

These atoms are the ions, that are charged, and the charged ions make bonds with each other to form compounds. Aluminum oxide is a compound that is formed by combining aluminum and oxygen atoms.

The compound is 3Al₂O₃

This means there are three moles of aluminum, and three moles of oxygen.

2 Al atoms + 3 O atoms = 5 Al₂O₃ atoms

5 Al₂O₃ atoms x 3 = 15

The elaborative way is:

2 Al atoms x 3 = 6 Al atoms

3 O atoms x 3 = 9 O atoms

6 + 9 =15 atoms total

Thus, the number of atoms is 15 atoms.

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Answer:

Explanation:

Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.

Answer:

B

Explanation:

Mass number  = number of neutrons + number of protons

Atomic number is the number of protons in the nucleus.  

58Ni   : 58 is the number of neutrons + number of protons

atomic number of Ni is 28.  Thus,  58 -28 = 30 neutrons

57Co ;  57 is the number of neutrons + number of protons

number of Co is 27. Thus, 57 – 27  = 30 neutrons

Explanation:

Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure

Answer:

Explanation:

Answer:

Inner space

Explanation:

I hope this helps

Answer:

Phosphorus trioxide

Explanation:

Answer:

Tetraphosphorus hexoxide

Explanation:

Give brainliest please

NO can't  be used to fill a balloon

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.

Answer options that need to be added :

a. Ne

b. NO

c. NH₃

d. CH₄

e. HF

will float in air ⇒ element or compound to fill the balloon, its density must be less than < 1.285 g/L

We can use the ideal gas formula ta find density :

[tex]\tt \rho=\dfrac{P.MW}{RT}[/tex]

Because at STP, then the constant value is

[tex]\tt \rho=\dfrac{1~atm\times MW}{0.08205\times 273.15~K}\\\\\rho=0.0446\times MW[/tex]

So that the density is determined from the MW(molecular weight) of each element or compound

Ar = 20.1797 g/mol

[tex]\tt \rho=0.0446\times 20.1797=0.9~g/L[/tex]

MW=30.006 g/mol

[tex]\tt \rho=0.0446\times 30.006=\boxed{\bold{1.338~g/L}}[/tex]

MW=17.0306 g/mol

[tex]\tt \rho=0.0446\times 17.0306=0.760~g/L[/tex]

MW=16.04 g/mol

[tex]\tt \rho=0.0446\times 16.04=0.715~g/L[/tex]

MW=20.01 g/mol

[tex]\tt \rho=0.0446\times 20.01=0.892~g/L[/tex]

Answer: 3:2

Explanation: (10.14÷3.38)÷(8.42÷4.21)=1.5=3/2

Answer:

Explanation:

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

From the question

density = 2 g/ml

volume = final volume of water - initial volume of water

volume = 508 - 500 = 8 mL

We have

mass = 2 × 8

We have the final answer as

Hope this helps you