All categories

3 years ago

What was johann dobereiners contribution to the development of the periodic table

2 answers:

7 0

He provided the base for the classification of elements he says the elements are atomic masses nearly same he arranged the atomic masses of the middle element is approximately the arithmetic mean of other two elements

KiRa [710]3 years ago

7 0

He put forward his laws in triads in 1817

You might be interested in

The mass percent of solute in a solution containing 3.73 g KBr dissolved in 131 g of H2O is:

Elina [12.6K]

$\huge \underbrace \mathfrak \red{Answer}$

28%

Explanation:

mass of solute(KBr) = 3.73g

mass of solvent(H2O) = 131g

mass of solution = mass of solute + mass of solvent

= 3.73 + 131

= 134.73g

$\sf \large {mass \: percentage = \frac{mass \: of \: solute}{mass \: of \: solvent} \times 100} \\ \\ \sf mass \: percentage = \frac{3.73}{134.73} \times 100 \\ \\ \sf mass \: percentage = 0.028 \times 100 \\ \\ \sf mass \: percentage = 28\%$

7 0

3 years ago

Fireworks change (blank) into (blank) and (blank) energy.

Nitella [24]

Fireworks changes chemical energy into light energy

5 0

4 years ago

Radioactive decay can be described by the following equation where is the original amount of the substance, is the amount of the

soldi70 [24.7K]

Answer:

Iron remains = 17.49 mg

Explanation:

Half life of iron -55 = 2.737 years (Source)

$t_{1/2}=\frac {ln\ 2}{k}$

Where, k is rate constant

So,

$k=\frac {ln\ 2}{t_{1/2}}$

$k=\frac {ln\ 2}{2.737}\ year^{-1}$

The rate constant, k = 0.2533 year⁻¹

Time = 2.41 years

$[A_0]$ = 32.2 mg

Using integrated rate law for first order kinetics as:

$[A_t]=[A_0]e^{-kt}$

Where,

$[A_t]$ is the concentration at time t

$[A_0]$ is the initial concentration

So,

$[A_t]=32.2\times e^{-0.2533\times 2.41}\ mg$

$[A_t]=32.2\times e^{-0.610453}\ mg$

$[A_t]=17.49\ mg$

<u>Iron remains = 17.49 mg</u>

8 0

3 years ago

Write the balanced chemical equation where liquid decane burns in oxygen gas to form carbon dioxide gas and water vapor. Use the

Allushta [10]

Answer:

$2C_{10} H_{22(l)} + 31O2(g)--> 20CO_{2(g)} + 22H_{2}O_{(g)}$

Explanation:

$2C_{10} H_{22(g)} + 31O2(g)--> 20CO_{2(g)} + 22H_{2}O_{(g)}$

From the question, one can work out which states of matter to assign to which species. The trick with organic equations of this nature is to try to balance everything but oxygen first. Make sure you balance oxygen last because it is the easiest to balance.

3 0

3 years ago

Someone tell me if I'm right

ahrayia [7]

The answer of perimeter to this question is 36

3 0

3 years ago