2. what is the factor in an experiment that a scientist wants to observe, which may change in response to
the manipulated variable; also known as a dependent variable​

Explanation:

so for this one u need to remember this equation and use it to find out moles= mass /mr . Mr of helium is 4

so moles= mass /mr

=100/4

=25 moles

hope this make sense:)

Answer:

b

Explanation:

Radar uses radio, and the siren uses sound waves, but both exhibit the Doppler effect. Therefore, option (C) is correct.

Radar operates by emitting radio waves and measuring the reflected waves to detect objects and determine their velocity. On the other hand, an approaching siren emits sound waves that propagate through the air.

Both radar and an approaching siren exhibit the Doppler effect. The Doppler effect is the change in frequency or pitch of waves (sound or electromagnetic) when the source of the waves and the observer are in relative motion. In the case of radar, the Doppler effect is used to measure the velocity of objects based on the frequency shift of the reflected radio waves. Similarly, the Doppler effect is observed with an approaching siren as the sound waves compress and the frequency appears higher as the source approaches the listener.

Therefore, both radar and an approaching siren differ in the type of waves they use (radio waves vs. sound waves), but they share the characteristic of exhibiting the Doppler effect.

Learn more about Doppler effect. here:

https://brainly.com/question/28106478

#SPJ5

Answer:

nucleus

Explanation:

thats 100% the answer

Answer:

0 kJ/mol

Explanation:

Step 1: Given data

Step 2: Calculate the Gibbs free energy change (ΔG)

We can calculate the Gibbs free energy change using the following expression.

ΔG = ΔH - T × ΔS

ΔG = 27 kJ/mol - 300 K × 0.09 kJ/mol.K = 0 kJ/mol

Since ΔG = 0 kJ/mol, the process in not spontaneous nor non-spontaneous.

Answer:

8 meters per second per second

Explanation:

Newton's second law: [tex]f=ma[/tex], force = mass multiplied by acceleration.

Therefore 56 / 7 = acceleration = 8

Answer:

0.333J/g°C is the specific heat of the metal

Explanation:

The heat that the metaal gives is equal to the heat that water is absorbing. The equation is:

S(metal)*ΔT(metal)*Mass(metal) = S(H2O)*ΔT(H2O)*Mass(H2O)

Where S is specific heat, ΔT is change in temperature and mass the mass in grams of the metal and water.

Replacing:

S(metal)*(100.0°C-27.2°C)*125.0g = 4.184J/g°C*(27.2°C-24.3°C)*250.0g

S(metal) = 4.184J/g°C*(27.2°C-24.3°C)*250.0g / (100.0°C-27.2°C)*125.0g

S(metal) = 0.333J/g°C is the specific heat of the metal

Answer:

Hail is a type of precipitation, or water in the atmosphere. Hail is formed when drops of water freeze together in the cold upper regions of thunderstorm clouds. These chunks of ice are called hailstones. Most hailstones measure between 5 millimeters and 15 centimeters in diameter, and can be round or jagged.

Explanation:

Answer:

Sample B has the highest specific heat

Explanation:

Specific heat of a material is defined as the heat necessary to increase in the temperature of 1g of material in 1°C.

The material with the highest specific heat requires more energy to increase its temperature.

In the problem, sample A and B are under the same amount of energy but sample A increases more its temperature. That means sample A has the lowest specific heat and:

Answer:

well I think it's false

I hope it helps

have a nice day

#Captainpower

Answer:

C 6 H 12 O 6 + 6 O 2 --> 6 CO 2 + 6 H 2 O + ATP is the complete balanced chemical formula for cellular respiration.

Answer:

Smaller

Explanation:

I took the test

Answer:

Explanation:

Ba(OH)₂ (aq) + 2HCl (aq) --> 2H₂O (l) + BaCl₂ (aq)

171 g                    2 x 36.5 g     2 x 18 g

73 g of HCl reacts with 171 g of Ba(OH)₂

125 g HCl reacts with 171 x 125 / 73 g of Ba(OH)₂

= 292.8 g of  of Ba(OH)₂

Ba(OH)₂  available is 250 g , so it is the limiting reagent .

171 g of Ba(OH)₂ forms 36 g of water

250 g of Ba(OH)₂ forms 36 x 250 / 171 g of water

= 52.63 g of water.

Answer:

V = 1.95 L.

Explanation:

Hell there!

In this case, according to the following reaction between sodium metal and water:

[tex]2Na+2H_2O\rightarrow 2NaOH+H_2[/tex]

We can realize that the moles of hydrogen can be calculated by using the initial mass of sodium, its atomic mass (23.0 g/mol) and the 2:1 mole ratio of sodium to hydrogen to obtain:

[tex]4.00gNa*\frac{1molNa}{23.0gNa} *\frac{1molH_2}{2molNa}=0.0870molH_2[/tex]

Finally, we calculate the volume of hydrogen by using the ideal gas equation whereas the pressure is 1 atm and the temperature 273.15 K according to the STP conditions:

[tex]PV=nRT\\\\V=\frac{nRT}{P}\\\\V=\frac{0.0870mol*0.08206\frac{atm*L}{mol*K}*273.15 K}{1 atm}\\\\V=1.95L[/tex]

Regards!

Answer:

Both hydrogen and oxygen gases exist as diatomic (“two-atom”) molecules. These molecules are the reactants in the reaction

Explanation:

:)

Answer: Wind, in climatology, the movement of air relative to the surface of the Earth. Winds play a significant role in determining and controlling climate and weather.

Answer:

Explanation:

b

Answer:

steel, plastics

Hope it helps!

Answer:

Atomic nuclei would fly apart

Explanation:

Answer:

(a) pH=4.0

(b) pH=8.3

Explanation:

Hello there!

In this case, since the pH is understood as the potential of the hydrogen in an aqueous solution, and we can calculate it is as follows:

[tex]pH=-log([H^+])[/tex]

We simply need to plug in the concentrations on each question as shown below:

(a)

[tex]pH=-log(1x10^{-4})\\\\pH=4[/tex]

(b)

[tex]pH=-log(5x10^{-9})\\\\pH=8.3[/tex]

Regards!

Answer: capillaries are not used to exchange substances between the body cells

Explanation:

Arteries carry blood away from the heart. Veins carry blood to the heart except the hepatic portal vein. Capillaries are used to exchange substances between body cells.

Answer:

decomposers

Explanation:

I'm not sure weather your supposed to create an actual experiment or write a paper. If an experiment, test certain acids to see which one can decompose plastics the fastest and determine which one can be spread through the oceans to melt down plastic. If a paper, discuss the idea of genetically modified fish. Some animals in the wild have the ability to eat pollution (wrappers, bottles, ect.), so mutating fish such as bottom feeders to be able to do the same would easily rid the water of pollution and make for one interesting of a paper! hope this sort of helped!

Answer:

Clean a platinum or nichrome (a nickel-chromium alloy) wire by dipping it into concentrated hydrochloric acid and then holding it in a hot Bunsen flame. Repeat this until the wire produces no color in the flame.

Answer:

13) What common form of energy (not including kinetic or potential) is not included in the “Energy Symbols” key that would normally be present in these examples?

1) Sound Energy

2) Magnetic Energy

14)Look carefully at each of the four systems shown above. Knowing what we have discussed about energy conversions, identify (list) at least three different places where this form of energy (sound) should be “produced”.

1) When you open the water tap, in the turbine and the sound of the light bulb.

2) In the light bulb

3) The sound of the kettle, the turbine and when water is boiling.

4) The movement of the wheel of the bicycle, the turbine and the light bulb.

Answer:

Human activity is by far the biggest cause of habitat loss.

Humans are now responsible for causing changes in the environment that hurt animals and plant species. We take up more space on Earth for our homes and cities. We pollute habitats. ... Human activity often changes or destroys the habitats that plants and animals need to survive.

Explanation:

Human activities are the various actions for recreation, living, or necessity done by people. For instance it includes leisure, entertainment, industry, recreation, war, and exercise.

Over time, destruction of such habitats leads to reduced biodiversity, weakening the Earth's ecosystems, and ultimately posing a major threat to human life. While, significant tracts of habitat have been lost, and along with them many species of plant and animal, steps can be taken to slow and even reverse the process.

One of the most significant ways in which humans have impacted on the lives of other species is by causing climate change. Many animals, including birds and frogs, now breed much earlier in spring in Britain than they did 20 years ago. Whether or not this is having a harmful effect on them has yet to be determined.

Answer:

22.4 L

hope it will help you

Answer:

A maybe I said maybe hope help

Explanation:

..