Air is classified as a mixture. What statement must be true about air? (4D)

a.) Air has a composition that is always the same mixture of elements and compounds.
b.) Air is made up of atoms of several different elements that are chemically combined.
c.) Air is made up of atoms of one element.
d.) Air is two or more elements or compounds that are not chemically combined.

Answers

Answer 1

Answer:

C.)Air is made up of atoms of one elements


Related Questions

When you take a hot shower, the
a
shower curtain sometimes moves
into the shower towards you. Why
does this happen?

Answers

With hot water comes hot steam, it fills the shower area with steam which raises the air temperature and the air then rises out of the shower

A substance that takes the shape and volume of its container is in this phase is called a liquid

Answers

Answer:

liquid matter

Explanation:

Please help me with this three questions

Answers

Answer:

1. A. Thyroid Gland Function

B. detecting Blood Clots

C. Treating Cancer

2. An example would be how many are used as tracers for diagnostic purposes

3. Beneficial because it gives us ways to eleminate pests, by the sterile insect technique

Number three is kinda iffy a bit difficult to explain it may be explained better in your book.

A chemist dilutes a 1. 0 mL sample of 2. 0 M KNO3 by adding water to it. If the concentration of the solution that is obtained is 0. 0080 M, what is its volume? Use M subscript i V subscript i equals M subscript f V subscript f. 125 mL 250 mL 500 mL 2,000 mL.

Answers

Answer:

We know the initial volume of the potassium nitrate solution is 1.0 mL and the initial concentration is 2.0 M, we also know that an unknown volume of water was added to the solution, which diluted our concentration down to a final value of 0.008 M. We are trying to find the final volume.

Here we can use this formula since the initial and final solutions are proportional. Before that let's define our variables.

[tex]M_1 = 2.0 M\\V_1 = \frac{1.0 mL}{1000} = 0.001 L\\M_2 = 0.008 M\\V_2 = \ ?[/tex]

[tex]M_{1}V_{1} =M_2 V_2\\[/tex]

[tex](2.0)(0.001) = (0.008)V_2\\\\\frac{(2.0)(0.001)}{0.008} = V_2\\\\V_2 = 0.25 L \ or \ (0.25 \ * \ 1000) = 250 \ mL[/tex]

Therefore you would have 0.25 L or 250 mL of your final solution.

Select the correct answer.
Tropical forests contain dense trees, which allow less sunlight to penetrate. Emergent trees are trees that grow to a height of more than 45 to 55 meters, above the usual height of trees in tropical forests. Which system provides the best possible explanation for why these trees grow to those heights?
A.
shunted growth pattern
B.
homeostasis
C.
due to less exposure to sunlight
D.
phototropism

Answers

B because if 7352x x 62 is 1936393 then u can divide that by 2 so it’s B

The bacteria are known to be prokaryotes. Prokaryote means

A
organisms whose cells have no nucleus
B
organisms who are made of many cells
C
organisms who make their own food
D
organisms whose cells have a nucleus

Answers

Answer:

prokaryote, also spelled procaryote, any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes. ... Bacteria are among the best-known prokaryotic organisms. The lack of internal membranes in prokaryotes distinguishes them from eukaryotes.

Explanation:

What is the molarity of a 75.0 mL solution that contains 0.225 g of
potassium nitrate?

Answers

Answer:

M=0.0297M

Explanation:

we know that molarity equals number of mole of solute over the volume of solution.

M=n/V but n=m/M

n=0.225g÷101g/mol =0.00223mol

M=0.00223mol/0.075l

M=0.0297M

Answer:

0.0297M

Explanation:

We will use the formula M= moles of solute/lites of solution.

First we need to figure out the Moles of the solute, to get this we first need the molar mass of KNO3 (potassimum nitrate).

The Molar Mass of potassimum nitrate is 101.103 g/mol
K - 1 x 39.09
N - 1 x 14.006
O - 3 x 15.999
KNO3 - 101.103 g/mol

Now we get the moles of the solute by doing.
0225g/ 101.103g/mol = 0.00223 mol

Put the answer into the orginal equation to get 0.00223mol / 0.045 L
Which equals to 0.0297M. This is also the correct amount of significant figures.

Mr. Green gave his students a set of items.


They had a toothpick, pencil, paper clip, safety pin, nail, and dime. He also gave them a magnet. He told them to predict which items are magnetic.

How can they test their predictions?
A.
weigh each of the items
B.
see which items stick to the pencil
C.
measure each of the items
D.
see which items stick to the magnet

Answers

Answer:

D. see which items stick to the magnet

Explanation:

To predict which items are magnetic, the students will have to test whether or not each item is attracted to the magnet. Only objects that are magnetic stick to a magnet, so all of the items that stick to the magnet should be magnetic.

Hopefully that's helpful! :)

What foods have been allowed or banned in which countries? Why?
please please help me

Answers

kinder eggs were banned in the US for a while because of a 1938 federal law that banned toys to be enclosed within food products.
Marmite was banned in Denmark in 2004 because of a law that resourced food products that were fortified with vitamins. Marmite had yeast extract. Technically, Denmark hasn’t banned Marmite, it’s more the additional vitamins minerals and such.
Haggis was banned in the US dba sue it contained sheep lung, which violates federal safety regulations.
McCain Brand French Fries have been banned in several countries, such as the UK and Australia, because it has a asthma including chemical called azodicarbonamide

3. Type: MT
Match the term to the correct definition
1. Homogeneous mixture
a. same throughout
2. Heterogeneous mixture
b. different throughout

Answers

Homogeneous mixture - same throughout

Heterogeneous mixture - different throughout

Answer:  Homogeneous Mixture : B(different throughout)

Heterogeneous Mixture : A(same throughout)


• If the distance between Earth and the Moon decreased by half, how would it affect the
weight of a person on Earth?

Answers

Answer:

look at the explanation

Explanation:

Tides would be much higher also A lunar month would be about 10 days rather than 29 days, so the phases of the moon would go much quicker.

PLEASE…. Select the number line that shows that two opposite numbers have a sum of

0.

3

A.

4321 01 2 3 4 5 6 7 8 9 10 11 12

B.

4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12

6

С.

-432-10 3 5 6 7 8 9 10 11 12

2

Answers

Answer:

C A

Explanation:

The the number line that shows that two opposite numbers have a sum of 0 is 4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12. The correct option is B.

What is number line?

A number line is a picture of a graduated straight line that serves as a visual representation of real numbers in elementary mathematics.

Every point on a number line is assumed to be a real number, and every real number is assumed to be a point.

4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12

We can see from this number line that the inverse of each number is located at an equal distance from 0.

For example, the inverse of 3 is -3, which is the same distance from 0 as 3. Similarly, the inverse of -1 is 1, which is the same distance from 0 as -1.

Thus, the correct option is B.

For more details regarding number line, visit:

https://brainly.com/question/16191404

#SPJ5

when an atom in an excited state returns to its ground state it

Answers

Answer:

Inside the Atom

Just like bricks are the building blocks of a home, atoms are the building blocks of matter. Matter is anything that has mass and takes up space (volume). All matter is made up of atoms. The atom has a nucleus, which contains particles of positive charge (protons) and particles of neutral charge (neutrons). Surrounding the nucleus of an atom are shells of electrons - small negatively charged particles. These shells are actually different energy levels and within the energy levels, the electrons orbit the nucleus of the atom.

Which statement describes why sodium reacts more vigorously than magnesium to hydrochloric acid? Refer to the periodic table. Circle the letter of the correct answer.

1) Sodium has a smaller atomic radius than magnesium.
2)Sodium has a lower ionization energy than magnesium.
3)Magnesium has a lower ionization energy than sodium.

Answers

Answer:

Its B all the others arent true and also dont make any sense

Explanation:

Sodium has a lower ionization energy than magnesium describes why sodium reacts vigorously than magnesium chloride.

Why is sodium more reactive than magnesium?Sodium is more reactive than magnesium because it has the ability to easily lose electron, hence have lower ionization energy.Sodium belong to group one on the periodic table and they are called akali metal while magnesium belong to group two on the periodic table and they are called alkali Earth metal.

Sodium and magnesium belong to the in the 3rd period. Iin the outermost energy level sodium has one electron but magnesium has 2 electrons. Therefore, there is more attraction abetween the nucleus and electrons in magnesium than that of sodium.

Therefore, sodium is more reactive than magnesium chloride because of lower ionization energy.

For more details on sodium reactivity, check the link below.

https://brainly.com/question/6837593

Elements that are usually shiny and good conductors of heat and electricity are known as_______.

Points: 70

Answers

metals. the metals take up most of the periodic table left of the metaloid staircase and also exclude hydrogen

Why is eating animals to obtain energy considered exothermic

Answers

Its considered exothermic because it helps then stay cool or and hot

Which animal is found in the desert?

monkeys

parrots

buffalo

meerkats

Answers

Answer:

meerkats

Explanation:

Which of the following could be classified as producing a physical change?
A. Burning a candle
B. Leaving a bicycle outside to rust
C. Bending sheet metal
D. Toasting a slice of bread

Answers

D which is Toasting a slice of bread

Answer:

C.  Bending sheet metal.

Explanation:

The metal is still intact.  No change in chemical bonds have occurred.

Burning a candle is converting wax into heat, CO2 and carbon soot.

A rusting bicycle is converting goof iron, Fe, into iron oxide (rust, Fe2O3)

Toasting bread is more difficult to define.  If the bread is just warmed, then it is physical.  If it is toasted (browned/burned), then a few surface molecules have been converted into tasty carcinogens, my favorite poison.

using the two ways you have learned about between temperature, pressure and volume, what are two ways you could increase the gas pressure of a system.

Answers

Answer:

I don't know do you know tell me please

please help me on this question plizzźzz

what is the green colouring matter found in plants called​

Answers

Answer:

the answer is chlorophyll....

Explanation:

if u need it's purpose just let me know

Explanation:

the green colouring matter found in plants is called chlorophyll.

The pH scale is used to tell if a substance
is an acid or base. Substances with a pH
of 7 are neutral. An acid is anything
below 7 and a base is anything above
7.What would a household cleaner with a
pH of 10 be considered on the pH scale?

Answers

Answer:

Explanation:

pH > 7   as 10 is more than 7

The cleaner is very corrosive.

It is a moderately basic. If it was 12 that would make it much more basic (100 times more basic).

What products are obtained by the electrolysis of CuSO4 solution using copper electrode ? Show with help of chemical reaction.​

Answers

Answer: The products will be copper and oxygen.

Explanation: Copper electorde is an active electrode so it constantly takes part in the electrolysis. Cathode is a pure copper negative electrode and anode is a impure copper positive electrode. So the copper present in the solution, along with the copper present in the anode will come off and go to the cathode. As a result, cathode gains copper. And the remaining impurities settle down in the bottom.

In the anode, oxygen will be given off because according to the order of discharge, if SO4 is present then the ions will stay in the solution and oxygen will be released. So at the end, solution of SO4 and H2O will be remaining while copper and oxygen is extracted.

The half equations are-

Cathode: Cu2+ + 2e- = Cu

Anode: Cu + 2e- = Cu2+

Something you might not know: The solution in electrolysis turns blue when copper goes to the cathode. So copper electrodes are also used in electroplating.

What is photosynthesis?​

Answers

Explanation:

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.

Answer:

photosynthesis is the process of making food by green plants by using sunlight,carbon dioxide, water.

I WILL GIVE BRAINLIEST TO THE RIGHT ANSWER

Which of the following substances would have the strongest
intermolecular forces of attraction present? *

A) HF (Hydrogen Fluoride)
B) HCI (Hydrogen Chloride)
C) HBr (Hydrogen Bromide)
D) HI (Hidrogen lodide)

Answers

Answer:

A) HF (Hydrofluoric acid)

Explanation:

dw I gotchu. So first off there are three types of intermolecular forces of attraction: 1) London-Dispersion, 2) Dipole-Dipole, 3) Hydrogen-Bonding Attraction Forces. That is also ranked in increasing strength, with Hydrogen-Bonding Attraction Forces being the strongest. Every molecule has London-Dispersion forces present and all the diatomic molecules listed have dipole moments of a certain debye (or Coloumb-meter) value. Both are irrelevant here so dw about that. Lets look at the strongest attraction: the hydrogen-bonding one. Now, don't get confused bc all of these acids are bonded to H bc hydrogen-bonding attraction forces only occur when H is bonded to N, O, or F. So Process of Elimination, hydrofluoric acid (HF) has the strongest intermolecular forces of attraction.

Note: If you don't know what inter/intra molecular forces of attraction are, ill give u a quick summary. Intermolecular refers to electrostatic attractions between molecules while intramolecular refers to the actual bonds, single, double, or triple, binding the atoms together. Well there you have it, have a great day. :)

Zn-71 has a half life of 2.4 minutes. If one had 100g at the beginning, how many grams would be left after 12 minutes?

Answers

3.125g

Explanation

2.4 minutes = 1 half life

so 12 minutes = 5 half lives (12/2.4)

100g/2 = 50g (1 half life)

50g/2 = 25g (2 half lives)

25g/2 = 12.5g (3 half lives)

12.5g/2 = 6.25g (4 half lives)

6.25g/2 = 3.125g (5 half lives)

Which of the following is the strongest covalent bond?

Single bond
Double bond
Triple bond
Hydrogen bond

Answers

Answer:

Triple bond is the strongest bond

Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond order of three.

Answer:

single bond.

In a single covalent bond, when the electrons are shared between two s orbitals, the resulting bond is a sigma (σ) bond . Sigma bonds are the strongest covalent chemical bonds....!!

What is the volume in mL of 1 Kg of gold? The density of gold is 19.3 g/mL.

Answers

Answer:

Volume occupied is approx.  

38 ⋅ ML

Explanation:

Density  ρ = Mass  Volume  And thus  Volume  = Mass  ρ = 1.592 ⋅ l b × 454 ⋅ g ⋅ l b − 1 19.3 ⋅ g ⋅ m L − 1   =   ? ? ⋅ m L

during hybridization ______.

A) nature selects which organisms will survive and reproduce.
B) the nucleus of a cell is removed.
C) two organisms with desired traits are bred.
D) a single beneficial trait is bred into a species.​

Answers

Answer:

option C two organisms with desired traits are bred

Is it unbalanced or balanced if hydrogen reacts to iodine?

Answers

Answer:

unbalanced

Explanation:

because it is REACTing.

calculate the speed of a train that travels 540 km in 9 hours​

Answers

Answer:

s=d/t. d=540 t=9h

540÷90=6 km/h

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