Help with this question I don’t get it I will give out 30 points!!!

A type of marble has a density of 2.5 grams/marble. A box filled with marbles has a total mass of 300 grams determine the number

Maurinko [17]

Answer:

100

Explanation:

Step 1: Subtract 50 by 300 to find the total mass of the marbles

300 - 50 = 250

Not hard, right?

Step 2: Divide 250 by 2.5

250 ÷ 2.5 = 100

And... 100 is your answer :)

Hope this helps :)

-jp524

4 0

3 years ago

How did the growth of the economy affect the status of women society?

zhenek [66]

You fine fr you need to stop playing games and hml so i can hit it from the back ma!!!!!

5 0

3 years ago

How many grams of NaCl should be added to 250 grams of waterto make a 0.40 m solution?

brilliants [131]

Answer:

5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.

Explanation:

$molality=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{ Mass of solvent (kg)}}$

Mass of NaCl =x

Molar mass of NaCl = 58.5 g/mol

Molality of the solution = 0.40 m

Mass of the solvent = 250 g = 0.250 kg (1g = 0.001 kg)

$0.40 m=\frac{x}{58.5 g/mol\times 0.250 kg}$

$x=0.40 m\times 58.5 g/mol\times 0.250 kg=5.85 g$

5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.

7 0

3 years ago

What is another name for a homogeneous mixture

nasty-shy [4]

The term "solution" is more frequently used when a homogeneous mixture is a liquid, although it is sometimes used if the homogeneous mixture is a gas.

7 0

4 years ago

Read 2 more answers

A fossil you are radiometrically dating contains 4 micrograms of Uranium 235 and 4 micrograms of Lead 207. Uranium 235 decays to

Rzqust [24]

The rate at which radioactive substances disintegrate is a constant for a

given radioactive material.

The fossil is 710 million years old.

Reasons:

The half-life of a radioactive material is the time it takes half of the nucleus

of a radioactive material to disintegrate into other forms of materials

through the given off of energy and particles.

The half life of Uranium 235 = 710 million years

The product of the decay of Uranium 235 = Lead 207

The mass of Uranium 235 in the fossil = 4 micrograms

The mass of Lead 207 in the sample = 4 micrograms

Therefore, the mass of Lead 207 in the fossil is equal to the mass of

Uranium 235, therefore, a minimum of half of the Uranium 235 has

decomposed, which gives;

The time of decomposition of the Uranium 235 = 1 Half life = 710 million years

The age of the fossil = The time in which the Uranium has been

decomposing = The time of decomposition = 1 half life of Uranium 235 = 710

million years

The age of the fossil = 710 million years

Using the formula for half-life, we get;

$\displaystyle N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}}$

The fossil contains initially only Uranium 235 with a minimum mass of 4 mg

+ 4 mg = 8 mg, which gives;

N₀ = 8 mg

N(t) = The current mass of Uranium 235 = 4 mg

$\displaystyle t_{1/2}$ = 710 million years

$\displaystyle 4 = 8 \cdot \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

$\displaystyle \frac{4}{8} = \frac{1}{2} = \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

Therefore;

$\displaystyle \left( \frac{1}{2}\right)^1 = \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

$\displaystyle 1 = {\dfrac{t}{710}$

t = 710

The age of the fossil, t = 710 million years

Learn more here:

brainly.com/question/20629992

3 0

2 years ago