Which of the isotopes are radioactive? Check all that apply.
hydrogen-1
hydrogen-3
helium-4
carbon-14
uranium-235
copernicium-277
fermium-252
carbon-12

Answer:

1, you should use candles for experiments because, You created an area of low pressure! When the experiment is run you can see tiny bubbles escaping under the glass which shows that the increased air pressure from the heated air as the candle burns. Once the candle runs out of oxygen, the candle burns out and the remaining air inside cools down.

2. you should put candles on sand trays, Pour layers of sand into a glass vase, alternating colors with each layer. For a more interesting look, try uneven layers in various heights. Keep layering sand until you're a few inches from the top of the vase. Place your votive candle in the center of the sand.

Explanation:

its scientific proven

Answer:

Correct answer-C 5.3g

Explanation:

Molarity = no. of moles of solute/ volume of of solution in litre

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,so the mass of 0.03125 moles of AgNO3 = 0.03125×169.87= 5.3084g

The grams of AgNO₃ are needed to prepare 0.125 M solution in 250 mL of water is 5.3 grams.

Moles is a unit which is used to define any amount and it is calculated as:

n = W/M, where

W = required mass

M = molar mass

Given molarity of AgNO₃ = 0.125 M

Volume of water = 250mL = 0.25L

moles (n) from the molarity (M) will be calculated as:

n = M × V

n = (0.125)(0.25) = 0.0312 moles

Now we calculate the mass of AgNO₃ by using the above formula as:

W = (0.0312mol)(169.87g/mol)

W = 5.30 g

Hence option (c) is correct.

To know more about moles, visit the below link:

https://brainly.com/question/15374113

Answer:

Acid–base indicators are generally weak protolytes that change color in solution according to the pH. The acid–base equilibrium of a weak acid type of indicator (HI) in water can be represented as. [I] The acid, HI, and the conjugate base, I−, have different colors. The equilibrium expression for this process is.

Explanation:

Answer:

it would be 100 km/hr

Explanation:

if you divide each speed by the time you get 100 each time

Answer:

Cooling is at the bottom, Pressure is in the middle, and Settling is at the top

Answer: Heat Q = m·c·ΔT

Explanation: Mass of 1.00 mol water m= 18.016 g. Heat capacity of water is

c= 4.19 J/( g K) and change of temperature ΔT= 100 K

Answer:

it's broken down into  carbon dioxide and water

Explanation:

The answer is A. It gets broken down.

Answer:

K2Cr2O7

Explanation:

Solubility refers to the amount of substance that dissolves in a given mass or volume of solvent. There are several units of solubility applicable in different areas.

Solubility is dependent on temperature. The solubility curve is a graphical representation of the dependence of solubility on temperature for different chemical species.

If we study the solubility curve closely, we will see that K2Cr2O7 has the highest solubility at 100°C. This means that if the trends continue, this substance will also have the highest solubility at 120°C.

Answer: c

Explanation:

Answer: The volume occupied by He is 62.4 L

Explanation:

According to ideal gas equation:

[tex]PV=nRT[/tex]

P = pressure of gas = 0.980 atm

V = Volume of gas = ?

n = number of moles = 2.50 mol

R = gas constant =

T =temperature =[tex]25.0^0C=(25.0+273)K=298.0K[/tex]

[tex]V=\frac{nRT}{P}[/tex]

[tex]V=\frac{2.50mol\times 0.0821 Latm/K mol\times 298.0K}{0.980atm}=62.4L[/tex]

Thus the volume occupied by He is 62.4 L

Answer:

Endothermic means: accompanied by or requiring the absorption of heat. So therefor cold packs would not be endothermic because they don't release cold. Instead they absorb heat

Explanation:

Answer:

Explanation:

Endothermic means accompanied by or requiring the absorption of heat, this view is not accurate because cold absorbs heat.

Answer:

D

Explanation:

The offspring of the RRYY x rryy cross, which is called the F1 generation, were all heterozygous plants with round, yellow seeds and the genotype RrYy. As you see, the letters (RrYy) gave uppercase, then lowercase

Answer:

$100

Explanation:

550/7=50

50×2=100

Answer: 9. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

10. The reasons for the differences in the surface temperature of terrestrial planets are due to their distance from the sun and the composition of their atmosphere.

11. 93.48 million miles

12. Iron core

Explanation: Hope this helped!! :)

Answer:

607.9616 grams

Explanation:

Answer:

Neodymium makes flints inside of lighters. It also takes away the green color off of glass. Rhenium is added with tungsten and molybdenum which makes filaments for lamps. Sulfur makes sulfuric acid which makes batteries and cleaners and can process ores.

Explanation:

An interesting fact for each element:

Neodymium is known for the atomic symbol Nd and the atomic number 60.

Rhenium is known for the atomic symbol Re and the atomic number 75.

Sulfur is known for the atomic symbol S and the atomic number 16.

I hope the Answer answers your question. I gave you some facts to remember those elements in the periodic table!

Neodymium(III) bromide, NdF3, neodymium(III) chloride, NdCl3, neodymium(III) bromide, NdBr3, and neodymium(III) iodide, NdI3, are the results of its reactions with fluorine, chlorine, bromine, and iodine.

Learn more about neodymium brainly.com/question/18012256

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Answer:

279.225g

Explanation:

The scientific method is an empirical method of acquiring knowledge.

These are the 5 scientific methods:

Answer:

0.0300 moles of H₂

Explanation:

The original equation is PV = nRT. We need to change this to show moles (n).

n = [tex]\frac{PV}{RT}[/tex]

It's important to convert your values to match the constant (r) in terms of units.

30.0 kPa = 0.296 atm

2500 mL = 2.50 L

27 °C = 300 K

Now, plug those values in to solve:

n = [tex]\frac{(0.296)(2.50)}{(0.0821)(300)}[/tex]    -  for the sake of keeping the problem clean, I didn't include the units but you should just to make sure everything cancels out :)

Finally, you are left with n = 0.0300 moles of H₂

Answer:

[tex]T_2=98.5^{\circ}[/tex]

Explanation:

Given that,

The specific heat of water is 4.184Jg°C

Mass, m = 600 g

Initial temperature, T₁ = 75.5°C

We need to find the final temperature. We know that heat absorbed is given by :

[tex]Q=mc\Delta T\\\\Q=mc(T_2-T_1)\\\\\dfrac{Q}{mc}=(T_2-T_1)\\\\\\T_2=\dfrac{Q}{mc}+T_1\\\\T_2=\dfrac{5.9\times 10^4}{600\times 4.184}+75\\\\T_2=98.5^{\circ}[/tex]

So, the final temperature is equal to [tex]98.5^{\circ}[/tex].

Answer:

because water wets stuff expect for fire.

Answer:

The meaning of wet is covered or saturated with water or another liquid, showing that is a glass is covered in water it is considered wet.

Explanation:

Answer:

synthesis reaction

Explanation:

synthesis reaction where reactants unite to form a single product.

Answer:

the pressure in the pipe in the case when there is no net force on the car is  81,726 N/m^2

Explanation:

a. The computation of the pressure in the pipe in the case when there is no net force on the car is shown below

As we know that

Pressure = F ÷ area

Also

F = mg

Now

= (1500 × 9.8) ÷π (0.24)^2

= 81,726 N/m^2

Hence, the pressure in the pipe in the case when there is no net force on the car is  81,726 N/m^2

Answer:

Explanation:

1. Mass number

2. Protons

3. Electrons

Answer:allow for greater chances for a sentinel event

Explanation:

Answer:

The last one

Explanation:

To much eye contact may cause discomfort to the patient. I mean like looking at the client is good but with out a blink breaking is weird.

Explanation:

I am not sure without knowing the name of the solutions. But according to me it can be happen which are D bcz when two solutions for e.g acid and base are mixed together, it changes its colour an form salts.

Answer:

Done and done

Explanation: