The diagram represents a section of Earth that a paleontologist, a
scientist who studies fossils, has been working with for years. Which
statement correctly describes this diagram?
a
b
Layer W contains fossils of organisms that existed on Earth after the organisms found in layers U and R.
Layer U contains fossils of organisms that are older than the organisms found in layer R.
Layers W and U contain fossils that are animal species.
Layers R and W contain fossils that are both types of plant species.
C с
Od

Answer:

Explanation:

  3BaBr₂       +       2Na₃PO₄     =       6BaBr + Ba₃(PO₄)₂ (s)

3 x 297 = 891 gm                                          1 x 602 = 602 gm

891 gram of BaBr₂ yields     602 gram of precipitate

15.2 gram of BaBr₂ yields     602 x 15.2 / 891 gram of precipitate

= 10.23 gram

actual yield = 9.5 gram

percent yield = 9.5 x 100 / 10.23

= 92.86 % .

Answer:

4.5 times 10 = 45

Explanation:

"Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."

Answer:

Explanation:

The density of a substance can be found by using the formula

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

From the question we have

[tex]density = \frac{45.3}{60} \\ = 0.755[/tex]

We have the final answer as

Hope this helps you

Answer:

500N/m²

Explanation:

The Pressure can be calculated using the formula:

P = F/A

Where;

F = force (N)

A = Area (m²)

Based on the information provided in the question, F = 30N, A = 0.06m²

P = F/A

P = 30/0.06

P = 500N/m²

Answer:

Na + + e - → Na.

Pb 2+ + 2e - → Pb.

2H + + 2e - → H 2

Explanation:

Answer:

mabye C at least if its not right sorry .

Answer:

B) 14g of nitrogen

Explanation:

To calculate number of molecules in 9g of water, we first convert mass to mole by using mole = mass/molar mass i.e.

mole = 9g/18g/mol of water

mole = 0.5mol

Next, we multiply by 6.022 × 10^23 molecules to get 3.011 × 10^23 molecules in 9g of water (H2O).

- For hydrogen gas: Molar Mass = 2g/mol, mass = 2g

mole = 2/2 = 1

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For Nitrogen gas: Molar Mass = 28g/mol, mass = 14g

mole = 14/28 = 0.5mol

No. of molecules = 0.5 × 6.022 × 10^23 = 3.011 × 10^23 molecules.

- For Oxygen gas: Molar Mass = 32g/mol, mass = 32g

mole = 32/32 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For carbondioxide gas: Molar Mass = 44g/mol, mass = 44g

mole = 44/44 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

Based on he results of each calculation, NITROGEN contains the same number of molecules as 9g of water

Answer:5) super Volcano eruption

Explanation:

Answer:

#1, #2, #4, and #6 are the answers.

Explanation:

#2, #4, and #6 have something to do with radioactivity which is mostly categorized in nuclear reactions, #3 and #5 are partly categorized in thermal reactions while a chemical plant explosion is almost categorized as a chemical bomb; Chemical explosions may be either decomposition or combination reactions. Decomposition reactions occur in materials such as trinitrotoluene (TNT) and nitroglycerine. Combination reactions require that two or more components react together exothermically to produce hot gases. Some examples are ammonium nitrate and fuel oil (ANFO), and gunpowder (potassium nitrate, carbon, and sulfur). In conclusion, #1, #2, #4 and #6 are the answers.

Answer:

1. 4

Explanation:

there are four atoms of hydrogen. you can tell because there is a 4 after the H.

Answer:

a

Explanation:

A world map showing the Principal World Air Masses. The four major types of air masses are noted on the map. The maritime polar has formed immediately north of Antarctica in the image.

The north Pacific Ocean produces the majority of the maritime polar air masses that affect the United States. However, maritime polar air occasionally forms in the North Atlantic Ocean and moves into the New England states.

In the winter, for example, an arctic air mass can move over the ocean, picking up some warmth and moisture from the warmer ocean and transforming into a maritime polar air mass (mP), which is still fairly cold but contains moisture.

In the image, the maritime polar has formed immediately north of Antarctica. The temperature of mP air varies between just above freezing and below 70 degrees Fahrenheit. As it moves over elevated terrain, mP air changes. Mountain ranges on the windward side

Thus, The maritime polar has formed immediately north of Antarctica in the image.

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Answer:

B. Cations are always the same size as the atoms from which they form.

Explanation:

That's i read in the book

"Anions are larger in size than the atoms from which they form" is a true statement. Therefore, option (C) is correct.

A cation contains more protons than electrons in it, which give it a net positive charge. A cation can be formed by losing one or more electrons must be lost by atoms.

The charge on the ion will be equal to the number of electrons lost as indicated after the chemical symbol. For example, silver (Ag) has lost one electron to become Ag⁺. The size of the cation is always smaller than the atom from which it formed.

An anion contains more electrons than protons which gives it a net negative charge. An anion can be formed by gaining one or more electrons or typically pulled away from other atoms.

The charge of the anion will be equal to the number of electrons gained, which is indicated after the chemical symbol.  For example, chlorine (Cl) accepts one electron to become Cl⁻.

The size of an anion is greater than the atoms from which it formed as the number of electrons in the ion increases and effective nuclear charge decreases.

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Answer:

A

Explanation:

The correct answer would be that a new substance is formed.

When magnesium wire is burnt in the presence of oxygen, the wire reacts with oxygen and a new substance known as magnesium oxide is formed. The new substance is usually white in color and the equation of the reaction is as below:

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

Hence, the correct option is A.

Answer:

Explanation:A new substance formed. Promise.

Answer:

In general, hot wet climates accelerate chemical weathering while cold dry climates accelerate physical weathering. Although the rate of weathering depends on the type of rock, rocks in tropical climates experience the highest rates of weathering because of the combination of high heat and heavy rainfall.

Answer:To calculate the Molarity of a 70 wt. % Nitric Acid the number of moles of HNO 3 present in 1 liter of acid needs to be calculated. Knowing the density of the acid to be 1.413 g/mL, we can calculate the weight of 1 L of 70% HNO 3 to be 1413

Explanation:

Answer:

Just say I wonder why teachers give homework :/

Explanation:

Answer:mark as brainliest

Explanation:H2SO4 and anhydrous calcium chloride CaCl2 are not used to dry ammonia because they react with it. The gas is passed through fresh quicklime (solid calcium oxide lumps) to effectively dry it.

Explanation:

The atomic mass of elements on the periodic table are derived from the proportion of the geonormal abundance of the different isotopes of an element.

Answer:what defino? I don’t see nun

Explanation:

Answer:

answer in picture

Explanation:

Answer:

Erosion, and soil damage

Explanation:

We do not use the plutonium (Pu) from reprocessed / used nuclear fuel because Plutonium has high rate of spontaneous fission and Uranium is the main fuel which is used for nuclear reactor.

A nuclear reactor is a device which is used to initiate and control a chain reaction to release large amount of steady heat there by produces energy.

Thus from above conclusion we can say that We do not use the plutonium (Pu) from reprocessed / used nuclear fuel because (i) Plutonium has high rate of spontaneous fission and (ii) Uranium is the main fuel which is used for nuclear reactor.

Learn more about the Nuclear reactor here: https://brainly.com/question/23160065
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Answer:

[tex]Speed = 670.56 \frac{m}{min}[/tex]

Explanation:

Given

[tex]Speed = \frac{25 mi}{hr}[/tex]

Required

Convert to meters per minutes

[tex]Speed = \frac{25 mi}{hr}[/tex]

Start by converting the speed from miles to meters

[tex]1\ mile = 1609.34\ meters.[/tex]

So, we have:

[tex]Speed = \frac{25 * 1609.34\ m}{hr}[/tex]

[tex]Speed = \frac{40233.5\ m}{hr}[/tex]

Next, we convert time from hours to minutes

[tex]1\ hour = 60\ minutes[/tex]

So, we have:

[tex]Speed = \frac{40233.5\ m}{60\ min}[/tex]

[tex]Speed = 670.56 \frac{m}{min}[/tex]

Hence, the equivalent of 25 miles per hour is 670.56 meters per minutes

Answer: lithium < strontium < magnesium < tellurium < chlorine < oxygen  

Explanation:

Ionization energy is the energy required to remove the most loosely bound electron from an isolated gaseous atom.

In a period, the ionization energy increases as we move across a period as the size decreases. The electrons get added to the same shell and the nuclear charge increases.The valence shell moves nearer to the nucleus.  Thus more energy is required to remove the valence electron.

In a group , the ionization energy decreases from top to bottom as we move down a group. The size increases as the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, lesser energy is required to remove the valence electron.

The correct order of increasing ionization energy will be:

lithium < strontium < magnesium < tellurium < chlorine < oxygen  

Ionization energy is the energy required to remove the most loosely bound electron from the last shell.

In the periodic table, there are groups and periods.

In a period, the ionization energy increases as we move across a period as the size decreases. The electrons get added to the same shell and the nuclear charge increases.

The valence shell moves nearer to the nucleus.  Thus more energy is required to remove the valence electron.

In a group, the ionization energy decreases from top to bottom as we move down a group.

The size increases as the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, lesser energy is required to remove the valence electron.

The correct order of increasing ionization energy is:

lithium < strontium < magnesium < tellurium < chlorine < oxygen

For more information, refer to the link:-

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Answer:

4 valence electrons.

Explanation:

Reaction 1 : yes

Reaction 2 : no

The metal activity series is expressed in voltaic series  

Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au  

The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent  

The more to the right, the metal is less reactive (harder to release electrons) and the stronger oxidizing agent

So that the metal located on the left can push the metal on the right in the redox reaction  

From activity series of Halogen :

F₂>Cl₂>Br₂>I₂

F₂ is the strongest oxidizing agent

1. Reaction

Cl₂ + 2Rbl - 2RbCI+ I₂

Cl₂>I₂⇒reaction can occur⇒yes, reactions will take place.

2. Reaction

I₂ + NiBr₂ - NI₂ + Br₂

Br₂>I₂⇒Reaction can't occur⇒no, reaction will not take place

Answer:

um okay lol

Explanation:

Answer:

Oh ok

Explanation:

Also can u pls mark me brainliest im new pls

Answer:

sodium I think .............

Answer:

D. P

Hope it works!

Explanation:

Answer:

Ca₃N₂

Explanation:

The empirical formula is the simplest whole-number ratio between moles of each element present in a molecule.

Thus, we need to convert mass of each atom to moles and find the ratio between these as follows:

Moles N:

1.46g * (1mol / 14.0067g) = 0.104moles

Moles Ca:

6.27g * (1mol / 40.078g) = 0.156moles

The ratio between Moles N and moles of Ca is:

0.156moles / 0.104 moles = 1.5

That means there are 1.5 moles of Ca per mole of N. As empirical formula must be given in whole numbers:

There are 3 moles of Ca per 2 moles of N.

Empirical formula is:

Answer:

I do believe the answer is false.

Hope This Helps!!