S, selentum 83 has a half life

When an irregularly shaped chunk of an unknown metal with a mass of 25.32 g was placed in a graduated cylinder containing 25.00

inn [45]

Answer: The density of the unknown metal is 7.86 g/ml.

Explanation:

Density is defined as the mass contained per unit volume.

$Density=\frac{mass}{Volume}$

Given : Mass of metal = 25.32 g

Volume of metal = volume of water displaced = (28.22 - 25.00) ml = 3.22 ml

Putting in the values we get:

$density=\frac{25.32g}{3.22ml}$

$Density=7.86g/ml$

Thus the density of the unknown metal is 7.86 g/ml

7 0

3 years ago

Suppose you are working with a NaOH stock solution but you need a solution with a lower concentration for your experiment. Calcu

Monica [59]

Answer: The volume of the 1.224 M NaOH solution needed is 26.16 mL

Explanation:

In order to prepare the dilute NaOH solution, solvent is added to a given amount of the NaOH stock solution up to a final volume of 250.0 mL.

Since only solvent is added, the amount of the solute, NaOH, in the dilute solution is the same as in the volume taken from the stock solution.

Molarity (M) is calculated from the following equation:

M = n ÷ V

where n is the number of moles of the solute in the solution, and V is the volume of the solution.

Accordingly, the number of moles of the solute is given by

n = M x V

Now, let's designate the stock NaOH solution and the dilute solution as (1) and (2), respectively . The number of moles of NaOH in each of these solutions is:

n (1) = M (1) x V (1)

n (2) = M (2) x V (2)

As the amount of NaOH in the dilute solution is the same as in the volume taken from the stock solution,

n (1) = n (2)

and

M (1) x V (1) = M (2) x V (2)

For the stock solution, M (1) = 1.244 M, and V (1) is the volume needed. For the dilute solution, M (2) = 0,1281 M, and V (2) = 250.0 mL.

The volume of the stock solution needed, V (1), is calculated as follows:

V (1) = M (2) x V (2) ÷ M (1)

V (1) = 0.1281 M x 250.0 mL ÷ 1.224 M

V (1) = 26.16 mL

The volume of the 1.224 M NaOH solution needed is 26.16 mL.

7 0

3 years ago

True or False: In a compound, the combination of elements is always different

dmitriy555 [2]

Answer:

in some cases this is true a compound is a mixture of elements although it is actualy false the diffrence is actualy baced on what elements it is made of like sulfur Dioxide is when sulfur reacts with the contents of the air when burning and reacting but they arnt always diffrent most caces it is just what element you use.

Explanation:

7 0

2 years ago

Number of electrons for all of these even the ones with a number by them ? Will give brainlist!!!!

Bumek [7]

Explanation:

s=2

p=6

d=10

f=14

pls mark me brainlist

7 0

2 years ago

What is a level 7-8 grade science fair project I can do?

Delicious77 [7]

Making an atom or a virus structure

4 0

3 years ago