Quantitative is a description in numbers , and qualitative is a description with words
A law is statement about an observed concept. A theory involves the explanation of scientific concepts or principles. A hypothesis is the predicted explanation about some concepts that has to be tested in order to prove it to be right. An observation is the observing the results of a scientific experiment carried out to test an hypothesis.
Here the given statement 'A chemist mixes sodium with water and witnesses a violent reaction between the metal and water,' can be classified as an observation as it explains what the chemists observes as a result of his chemical experiment or test..
Explanation:
As you move across the periodic table, the number of protons and neutrons increases but the number of orbital levels of the period remains the same. The atomic radii therefore decrease, across the period, because the increase in proton number causes an increased pull of the orbital electrons bringing them closer to the nucleus.
As you move down a group in a periodic table, the number of orbital levels increase. The effective nuclear charge of the nucleus of the atoms decreases due to the increased number of orbital levels that shield the valence electrons from the attractive force nucleus.
Answer:
2.5×10⁶ s
Explanation:
From the question given above, the following data were obtained:
Rate constant (K) = 2.8×10¯⁷ s¯¹
Half-life (t½) =?
The half-life of a first order reaction is given by:
Half-life (t½) = 0.693 / Rate constant (K)
t½ = 0.693 / K
With the above formula, we can obtain the half-life of the reaction as follow:
Rate constant (K) = 2.8×10¯⁷ s¯¹
Half-life (t½) =?
t½ = 0.693 / K
t½ = 0.693 / 2.8×10¯⁷
t½ = 2.5×10⁶ s
Therefore, the half-life of the reaction is 2.5×10⁶ s
Evaporation and transpiration
