Read the passage below and choose the best answer for the main idea of the passage:
Footprints offer clues about where we came from and where we're headed. Their impressions tell us something
about the animals that leave them. But while actual footprints offer details on size, weight and speed, carbon
footprints measure how much carbon dioxide (CO2) we produce just by going about our daily lives. A drive to work,
a flip of a light switch and a flight out of town all rely on the combustion of fossil fuels like oil, coal and gas. When
fossil fuels burn, they emit greenhouse gases like CO2 that contribute to global warming. Ninety-eight percent of
atmospheric CO2 comes from the combustion of fossil fuels.
a. Footprints come in all shapes and sizes.
C. Global warming comes from the emission of
CO2 into the atmosphere.
d. No one should be allowed to drive because
it causes global warming.
b. We study footprints to learn about the
animals who leave them.

Explanation:

the answer is in the attachment

Answer:

6amu

Explanation:

mass=proton+neutron

mass of cl2=2(16+16)=64amu

Answer:

genes

Explanation:

Answer:

228.7[tex]dm^{3}[/tex]

Explanation:

According to Boyle's law

P1V1 = P2V2

where P1& P2 are initial and final pressure

and V1& V2 and initial and final volumes respectively.

Given:

P1 = 136atm, P2 = 131.6atm

V1 = 142[tex]dm^{3}[/tex]; V2 = ?

V2 = [tex]\frac{P1V1}{P2}[/tex] = [tex]\frac{136*142}{131.6}[/tex]

= 146.7[tex]dm^{3}[/tex]

Total volume, V = V1 + V2

=146.7 + 142

= 228.7[tex]dm^{3}[/tex]

Answer:

A... Chemical change?

Explanation:

Im really sorry if this is wrong. Im d u m b

The volume of Sulfur dioxide-SO₂ at STP : = 102.144 L

Given

4.56 mol Sulfur dioxide-SO₂

Required

The volume

Solution

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.

so for 4.56 mol :

= 4.56 x 22.4 L

= 102.144 L

Answer:

c

Explanation:

I know it's c because I have done the test

Explanation:

The more reactive element replaces less reactive element during chemical reaction.

Since, potassium is more reactive than beryllium. When potassium reacts with beryllium choride, it replaces beryllium and forms potassium chloride and produces beryllium.

Beryllium is produced due to the fact that the more reactive element in the reaction would have to take over the element that is less reactive.

In this reaction the element that is more reactive is potassium. When the reaction takes place it would take over and replace beryllium due to this quality.

Hence beryllium chloride would become potassium chloride from the resulting reaction.

Read more on chemical reactions here:

https://brainly.com/question/11231920?source=archive

Answer:

There are 2.7× 1023atoms in 0.45 mol of Al.

Explanation:

Answer:

do not care

Explanation:

Answer:

Fossil Fuels are exhaustible natural resources, because they can't be renewed. Once these fuels are used up, there are NONE left! We can change that by reducing the amount we use. It takes millions of years for it to be remade, and we will soon die out before that happens. Thats why fossil fuels are exhaustible. :)

Explanation:

Hope this helps! :)

Explanation:

3Mg(s) + N2(g) = Mg3N2(s)

First check that the equation is balanced. In this case, it is.

Assuming that magnesium is the limiting reactant:

       We find that the atomic mass of magnesium is approximately

       24.3g, so the molecular weight is just 24.3g\mol

    2. Next we need the mole to mole ratio. As there are 3

        magnesiums for 1 magnesium nitride (shown by the coefficients), the                    

        mole to mole ratio is 1 mol Mg3N2\3 mol Mg.

    3. We need the amount of the substance, in grams. Since you have not    

        stated it in the question, I'll just do 10g AS AN EXAMPLE. Note that    

       depending on the amount, the LIMITING REAGENT MAY DIFFER.

   4.  Finally, we need the molecular weight of Mg3N2, which we can easily    

        calculate to be around 100.9\mol.

   5.  Putting this all together, we have 10gMg⋅ (mol Mg\24.3gMg)

        (1mol Mg3N2\ 3mol Mg) (100.9g Mg3N2\mol Mg3N2)

        the units will cancel to leave gMg3N2 (grams of magnesium nitride):

       10gMg ⋅ (mol Mg\24.3gMg) (1mol Mg3N2\3mol Mg)

       (100.9g Mg3N2\mol Mg3N2)

Doing the calculation yields approximately 13.84g.

Assuming that nitrogen is the limiting reactant:

Similarly, following the above steps but with 10g of nitrogen yields 36.04g

In conclusion, as we produce less amount of Mg3N2 when we assumed that Mg was the limiting reagent, magnesium is the limiting reagent and nitrogen is the excess.

Note: This is in THIS CASE, where we have 10g of both. The answer may vary depending on the amount of each substance.

Answer:

  1.46×10^25 molecules

Explanation:

Each mole of N₂ reacts with 3 moles of Mg to form 1 mole of Mg₃N₂. That is, the number of moles of product is equal to the number of moles of nitrogen gas when excess magnesium is present.

There are 6.022×10²³ molecules in each mole of a substance, so the number of molecules of Mg₃N₂ is

  (24.3 mol)(6.022×10²³ molecules/mol) = 1.46×10²⁵ molecules

Answer:

How likely something is to happen.

Answer:

12.92

Explanation:

Answer:

cells?

Explanation:

Answer:5.02228

Explanation: My bad I put it in scientific notation not standard. Sorry. Heres the right answer

Answer:

63.499%

Explanation:

Answer:

Asthenosphere

Explanation:

The asthenosphere is the hot, weak, inner part of the upper mantle. Although it is solid, it can flow like a thick, heavy liquid.

Answer:

what is the question i could help if u gave me the question but i don't see it  

Explanation:

Answer:

c

Explanation:

it is c but im not exactly sure

you have a 25% chance tho

sorry

2H₂+O₂⇒ 2H₂O

Given

Chemical equation :

2H₂+O₂⇒

Required

Compound produced

Solution

In determining the product that may be produced is to use the principle of the law of conservation of mass where the number of atoms/elements in the reaction either before the reaction (reactants) or after the reaction (products) is the same so that a balanced chemical equation is formed.

In the above reaction, there are two elements that play a role in the reaction, namely H and O

So that the resulting product also has these 2 elements, so we can ignore options A and C because there are elements C and Cl, while choice B does not contain the element H

The right choice: D

Answer:Iron combines with oxygen to produce rust, which is the compound named iron oxide

Explanation:

1. 12 L = 12 dm³

2. 3.18 g

Given

1. Reaction

K₂CO₃+2HNO₃⇒ 2KNO₃+H₂O+CO₂

69 g K₂CO₃

2. 0.03 mol/L Na₂CO₃

Required

1. volume of CO₂

2. mass Na₂CO₃

Solution

1. mol K₂CO₃(MW=138 g/mol) :

= 69 : 138

= 0.5

mol ratio of K₂CO₃ : CO₂ = 1 : 1, so mol CO₂ = 0.5

Assume at RTP(25 C, 1 atm) 1 mol gas = 24 L, so volume CO₂ :

= 0.5 x 24 L

= 12 L

2. M Na₂CO₃ = 0.03 M

Volume = 1 L

mol Na₂CO₃ :

= M x V

= 0.03 x 1

= 0.03 moles

Mass Na₂CO₃(MW=106 g/mol) :

= mol x MW

= 0.03 x 106

= 3.18 g

Answer:

welcome to 2021 dude

its been a long time since i answered this but here is my new account

Explanation:

Answer:

speed = 16 kilometers per hour

= 16 km/h

Explanation:

Mark brainliest plssssss

Answer:

the answer b because

The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles AgNO3, or 169.8731 grams.

Explanation:

Answer:

A

add a coefficient 2 before Fe and a 3 before H2O

Answer:

Option A. Add a coefficient 2 before Fe and a 3 before H2O

Explanation:

Fe₂O₃ + 3H₂ —> Fe + H₂O

The above equation can be balance by as follow:

Fe₂O₃ + 3H₂ —> Fe + H₂O

There are 2 atoms of Fe on the left side and 1 atom on the right side. It can be balance by putting 2 before Fe as shown below:

Fe₂O₃ + 3H₂ —> 2Fe + H₂O

There are 3 atoms of O on the left side and 1 atom on the right side. It can be balance by putting 3 before H₂O as shown below:

Fe₂O₃ + 3H₂ —> 2Fe + 3H₂O

Now the equation is balanced.

Thus, the student should add a coefficient 2 before Fe and a 3 before H2O

Mass of Cu : 95.319 g

Given

9.03 x 10²³atoms of Copper

Required

mass of Cu

Solution

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

Mol of Copper :

n = N/No

n = 9.03 x 10²³/6.02.10²³

n = 1.5

Mass of Copper :

= mol x Ar Cu

= 1.5 x 63,546 g/mol

= 95.319 g

9.03 × 10²³ atoms of copper have a mass of 95.3 g.

We want to convert 9.03 × 10²³ atoms of copper to grams. We will need a series of conversion factors.

A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.

The required conversion factor is Avogadro's number: there are 6.02 × 10²³ atoms in 1 mole of atoms.

9.03 × 10²³ atoms × (1 mol/6.02 × 10²³ atoms) = 1.50 mol

The required conversion factor is the molar mass of copper: 63.55 g/mol.

1.50 mol × 63.55 g/mol = 95.3 g

9.03 × 10²³ atoms of copper have a mass of 95.3 g.

Learn more about Avogadro's number here: https://brainly.com/question/7287712

what are the following things

Metals are good conductors and shows some peculiarities such as luster, ductility, malleability,etc. Brittleness is not associated with metals since they are hard. Hence option A is correct.

Metals are electropositive elements with good conductivity. Metals are classified into the s block and d block of periodic table. Thus alkali metals, alkaline earth metals and transition metals are the classes of metals.

Metals are rich in free electrons thereby, they capable of conducting electrically and thermally. Other features that metals have , they are hard and not brittle. Metals are malleable and ductile.

Malleability is the property by which it can be pressed into different shapes easily without cracking. Ductility means they can be plastically deformed into thin wires without fracture.

Metals are shining and this property is called lustrous. Hence all the properties such malleability, ductility and luster are features of metals but they are not brittle. Hence option A is correct.

To find more about metals, refer the link below;

https://brainly.com/question/18153051

#SPJ6

Your question is incomplete. But your complete question probably was:

Which of the following is NOT a property of metals associated with metallic bonds?

A Brittleness

B Malleability

C Ductility

D Luster