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Answer:

B (40º c)

Explanation:

Rubidium being silvery-white and melting at 39 ºC. Which means 40º C is the closest.

Answer:

NO

Explanation:

To maintain electric neutrality, the atom has to have equal number of electrons and protons. Therefore, it needs to have 6 electrons to be neutral.

Answer:

Hydrogen reacts with oxygen to form a compound called hydrogen peroxide so your answer is none of the above.

Explanation:

Hope it will help you :)

Answer:oxide

Explanation:

The reaction ofhydrogen and oxygen result on hydrgen peroxide which is a part is oxide

Answer:

Explanation:

It is a physical change. The reason is that when a straight piece of wire is coiled to form a spring, its chemical properties do not change. Only the physical property ( shape ) of the wire changes.

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Answer:

See below

Explanation:

If a piece of wire is coiled to form a spring, it is a physical change. This is because there is no change in it's bonds rather there is a change in its shape and figure. Also, Physical change is reversible such that the coiled piece of wire can be changed back to a straight piece of wire. But, A chemical change is irreversible.

So, This is a physical change.

Answer:

0.000745  megameters is the answer please mark me as brainliest

Answer:

Instantly Convert Millimeters (mm) to Megameters (Mm) and Many More Length Conversions Online. Millimeters Conversion Charts. Many Other ...

Missing: 745000× ‎| Must include: 745000

Answer:

To measure heat, you divide the change in temperature of a sample of water by the mass of the water.

Answer:

Acceleration, [tex]a=55.88\ m/s^2[/tex]

Explanation:

It is given that, A top fuel dragster is designed to go from 0 to 100 miles per hour in a mere 0.8.

Initial velocity, u = 0

Final velocity, v = 100 mph

1 mph = 0.44704 m/s

100 mph = 44.704 m/s

Time, t = 0.8 s

We need to find its acceleration. Rate of change of velocity equals acceleration.

[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{44.704-0}{0.8}\\\\a=55.88\ m/s^2[/tex]

So, the acceleration is [tex]55.88\ m/s^2[/tex]

Answer:

KI

Explanation:

Answer:

Hey there!

False. The growth rate is actually the birth rate minus the death rates.

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Answer:

It's importance is the fact that you cannot solve s situation if you don't know it's problem.

Explanation:

Problem identification or identifying a problem by scientist I a major and a key step in solving a problem.

I mean, if you don't identify a problem, there is no way you can think about the solution not to talk of getting the solution.

So identification of a problem is infact one of the major step a scientist must take to solve a situation.

It's importance is the fact that you cannot solve s situation if you don't know it's problem.

Answer:

The electronic configuration of the element with Atomic number 19 is 2,8,8,1. The element is potassium. It is an alkali metal with one valence electron.

Answer:

The first step is - option A) an acid base reaction.

Explanation:

The direct reaction of a carboxylic acid with an amine to form an amide is expected to be difficult as it would deprotonate the carboxylic acid and make a nonreactive carboxylate.

The first step in this reaction would be an acid - base reaction as protonation of the carbonyl carbon, that involves the interchange of proton in between electric charge or neutral compound, it is also known as protonation or deprotonation. The acid base reaction is followed by the nucleophilic attack on the carbonyl carbon.

Thus, The first step is - option A) an acid base reaction.

Answer:

3 × 10¯¹⁰

Explanation:

9×10² ÷ 3×10¹²

The above expression can be evaluated as follow:

9×10² ÷ 3×10¹²

Recall:

3² = 9

3¹ = 3

Therefore,

9×10² ÷ 3×10¹² = 3²×10² ÷ 3¹×10¹²

Recall:

y^m ÷ y^n = y^(m – n)

Therefore,

3²×10² ÷ 3×10¹² = 3²¯¹ × 10²¯¹²

= 3¹ × 10¯¹⁰

Recall:

y¹ = y

Therefore,

3¹ × 10¯¹⁰ = 3 × 10¯¹⁰

Therefore,

9×10² ÷ 3×10¹² = 3 × 10¯¹⁰

Answer : The correct statement is:

The density of each piece is the same as that of the original block.

Explanation :

Intensive property : It is defined as a property of substance which does not change as the amount of substance changes.

Examples: Temperature, refractive index, density, hardness, etc.

According to question, if Ana has a block made of pure gold and she cuts this block into two equal pieces then the density of each piece is the same as that of the original block because density is an intensive property that does not changes until and unless material is changed.

That means density remains same as that of the original piece.

Hence, the correct statement is the density of each piece is the same as that of the original block.

A food web is the interconnection of the various food chains. A herbivore is a primary consumer that feeds on the producers in a food web. Thus, option B is correct.

A primary consumer is an organism that appears second at the trophic level after the producers in an ecological pyramid of the food web and food chain. They feed on the producers to gain energy.

The primary consumer is herbivores as they mainly eat the producers that are planted in a food web. They get the maximum amount of energy as a consumer in a pyramid.

They only eat plants hence called herbivores. They get eaten by the secondary consumers that are omnivores and carnivores as they eat plants and animals both.

Therefore, option B. primary consumer are herbivore that eats producers.

Learn more about primary consumers here:

https://brainly.com/question/11173626

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Answer:

magnesium + hydrochloric acid → hydrogen gas + magnesium chloride

explanation:

the nitrogen in HNO3 is in the +5 oxidation state and is easily reduced. The reduction would result in the oxidation of the hydrogen gas, forming the water once again.The sulfur in H2SO4 is also in its highest oxidation state, +6.

Hope this helps :)

Answer:

Heat transferred, Q = 1542.42 J

Explanation:

Given that,

Mass of water, m = 30 grams

Initial temperature, [tex]T_i=25^{\circ} C[/tex]

Final temperature, [tex]T_f=12.7^{\circ} C[/tex]

We need to find the energy transferred. The energy transferred is given by :

[tex]Q=mc\Delta T[/tex]

c is specific heat of water, c = 4.18 J/g °C

So,

[tex]Q=30\ g\times 4.18\ J/g-^{\circ} C\times (12.7-25)\ ^{\circ} C\\\\Q=-1542.42\ J[/tex]

So, 1542.42 J of energy is transferred.

Answer and Explanation:

Given that

Length of race = 5km

Maximum speed = 45 yards

Based on the above information,

We transform the yards to kilometer i.e.

1 km = 1093.613 yards

And,  

x = 45 yards

So,

1093.613 × x = 45

x = 45 ÷ 1093.613

x = 0.0411480 km

Where

x = Maximum length for which the maximum speed demonstrated in kilometers is sustained.

So, we concluded that Lamor cannot go for the overall 5km as he maintained till 0.0411 km

Answer:

most likely water

Explanation:

most likely it is water, however pressure plays a role, if you are at sea level the boiling point of water is 100°C but if you are on Mt. Everest it is 71°C, assuming she is slightly above sea level it is water.

Answer:

The correct option is;

D Global warming would decrease the surface tension of water, making it harder for water striders to walk on water

Explanation:

Global warming involves the heating of the ecosystems on Earth due to human activity, which results in rising temperatures

As the temperature of the water rises due to global warming the surface tension decreases due to the increasing ratio of the force of higher kinetic energy water molecule to inter-molecular cohesive forces pulling the water together, which tends to weaken the effect of the cohesive forces and thus reduce the surface tension

As the surface tension has been reduced, the water striders will find it difficult to walk on the water surface as the maximum weight the water surface can lift without shearing, due to surface tension is reduced.

Answer:

Carbon is non metal because it is found in the right side of the periodic table while calcium is metal because it is found in the left side of the periodic table.

Answer:

Forests prevent desertification.

Explanation:

Answer:

Bow and arrow

Explanation:

A bow and arrow need accuracy to hit a target. It needs precision to hit the small target

Answer:

False

Explanation:

I hope this explanation was clear and comprehensive.

Answer:

wax, candlewick, and oxygen

Explanation:

The burning of the candle is both a physical as well as a chemical change. The reactants are the substances or the raw materials that are required for a reaction to the process. In the process of burning a candle, the reactants are the fuel which includes wax and wick, and oxygen which is found in the air. The products found at the end of the reaction are carbon dioxide and water vapor.

• Take a look at the steps below to see how to balance this equation. Let's start by writing the unbalanced equation given the information.

Unbalanced Equation : C₃H₈ (g) + O₂ (g) → CO₂ (g) + H₂O (g) ,

Start by Balancing the Carbons : C₃H₈ (g) + O₂ (g) → 3CO₂ (g) + H₂O (g)

Now let's balance the Hydrogen : C₃H₈ (g) + O₂ (g) → 3CO₂ (g) + 4H₂O (g)

Balancing the Oxygen : C₃H₈ (g) + 5O₂ (g) → 3CO₂ (g) + 4H₂O (g)

Balanced Equation : C₃H₈ (g) + 5O₂ (g) → 3CO₂ (g) + 4H₂O (g)

• Let's apply dimensional analysis here,

0.7 L propane × (5 liters Oxygen / 1 liter Propane) = 3.5 Liters of Oxygen

•  Similarly we can identify the liters of carbon dioxide produced in the reaction,

0.7 L propane × (3 liters Carbon Dioxide / 1 liter Propane) = 2.1 Liters of Carbon Dioxide

• 0.7 L propane × (4 liter water vapor / 1 liter propane ) = 2.8 Liters of Water Vapor