Answer:
It is mentioned that the student is mixing chemicals A and B and observes the time taken for the color to change. However, in the experiment, it is noticed that the student has repeated the procedure five times and each time he or she is modifying the concentration of chemical B. Thus, it is clear that the concentration of chemical B is the independent variable in the experiment. An independent variable is illustrated as the variable, which is controlled or modified in the experiment.
Answer:
0.071 moles of Na₃PO₄ .
Explanation:
Given data:
Number of molecules of Na₃PO₄ = 4.3× 10²² molecules
Number of moles = ?
Solution:
1 mole contain 6.022 × 10²³ molecules
4.3× 10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.71× 10⁻¹ mol
0.071 mol
The number 6.022 × 10²³ is called Avogadro number.
"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance"
Answer:
8.90
Explanation:
Density = mass ÷ volume
D = 222.50 g ÷ 25.00
= 8.9
The density of the unknown metal is 8.90.
Hope that helps.
Answer:
beta particle
Explanation:
Explanation:
Alpha beta and gamma radiations are the examples of ionizing radiations. When an atom is an excited state and having high energy, the atom is in unstable state. The excess of energy is released by the atom to get the stability. The released energy is in the form of radiations which may include alpha, beta, gamma, X-ray etc.
¹⁴₆C → ¹⁴₇N + ⁰₋₁e
The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.
Beta radiations:
Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminium is used to block the beta radiations
Fermentation occur in yeast is alcoholic.
