All categories

3 years ago

Compare the discoveries of Henri Becquerel with the discoveries of Marie Curie

2 answers:

7 0

Henri Becquerel is the first scientist who discover evidence of radioactivity.
Maria Curie is one of the most famous scientists in the world who invented the word "radioactivity". She discovered that radioactive materials gave out rays and discovered two elements: polonium and radium, which are extraordinary active.

julsineya [31]3 years ago

4 0

Answer:

Marie Curie discovered several radioactive elements.

Henri Becquerel discovered spontaneous radioactivity from uranium.

Both Marie Curie and Henri Becquerel made discoveries in the area of radioactivity.

Explanation:

edge2020

You might be interested in

Which statement is correct? A. pKa is not an indicator of acid strength. B. An acid with a small Ka is stronger than an acid wit

Svetradugi [14.3K]

Answer:

Explanation:

Since [pKa = - log Ka]....hence..,the larger the Ka value,the stronger the acid is..so this means that the pKa is vice versa

Saying that the smaller the pKa value..the stronger the acid is.

3 0

4 years ago

Read 2 more answers

A piece of an unknown substance weighing 124.0 grams is heated in boiling water to 100.0oc. when the substance is placed in a ca

MakcuM [25]

The heat cause 300g water temperature increase from 20 to 26 celcius. The heat transferred would be: 300g * (26 °C -20 °C) *4.2 joule/gram °C= 7560J

The unknown substance is added to the water, so its final temperature should be the same as the water. The calculation would be:

7560J= 124g * (100-26)* specific heat

specific heat= 7560J / 124g / 74 °C= 0.8238 J/gram °C

3 0

4 years ago

Why is Hawaii made of volcanoes? <br>

Vadim26 [7]

Answer:

Explanation:

The Hawaiian Islands were literally created from lots of volcanoes—they're a trail of volcanic eruptions. In the case of the Hawaiian Islands, the Pacific Plate is continually moving to the northwest over the Hawaiian hot spot. This movement caused the Hawaiian chain of islands to form.

8 0

3 years ago

The empirical formula of a compound is CH2O and its molecular weight is 90.09 g/mol. Determine the molecular formula.

Pachacha [2.7K]

Answer : The molecular formula of the compound will be, $C_{3}H_{6}O_3$

Explanation :

Empirical formula : It is the simplest form of the chemical formula which depicts the whole number of atoms of each element present in the compound.

Molecular formula : it is the chemical formula which depicts the actual number of atoms of each element present in the compound.

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

As we are given that the empirical formula of a compound is $CH_2O$ and the molar mass of compound is, 90.09 gram/mol.

The empirical mass of $CH_2O$ = 1(12) + 2(1) + 1(16) = 30 g/eq

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

$n=\frac{90.09}{30}=3$

Molecular formula = $(CH_2O)_n=(CH_2O)_3=C_{3}H_{6}O_3$

Thus, the molecular formula of the compound will be, $C_{3}H_{6}O_3$

7 0

4 years ago

What are the ion concentrations in a 0.12 M solution of AlCl3? A) 0.12 M Al3+ ions and 0.040 M Cl- ions B) none of the answers C

KIM [24]

Answer:

Explanation:

To answer this question, we will need to write the dissociation equation of aluminum trichloride.

AlCl3 ——-> Al3+ + 3Cl-

It can be seen that when aluminum chloride dissociates, it gives one mole of aluminum ion and three moles of the chloride ion.

From here we can see that the concentration of the aluminum chloride equals that of the aluminum ion while that of the chloride ion is thrice that of the aluminum chloride. This means we simply multiply 0.12M by 3 to get the molarity of the chloride ion while that of the aluminum ion remains the same

5 0

3 years ago