There are many ways to predict the properties of an element here's one example.As you move from left to right the electron affinity and ionization energy both increase .Since elements of the same family have similar characteristic,you can often predict the properties of another element in its family
Answer:
The contributions are not listed in the question. I guess the following are the options you are talking about.
Same elements have same properties:
In 1803 Dalton gave the atomic theory that the properties of the atoms of the same element are same.
Electrons in Orbits:
Electrons were discovered in 1897 by J J. Thompson but the hypothesis of electrons in the orbits were given by Hantaro Nagaoka in 1904.
Plum pudding model:
Plum pudding model was given by J. J. Thompson in 1904 with the concept of positively charged medium containing the negatively charged electrons in it.
Positively Charged Atomic Nucleus:
Earnest Rutherford in 1911 discovered the positively charged atomic nucleus.
What is wrong with the experimental design is that the student changed more than one independent variable.
WHAT AN EXPERIMENT SHOULD CONTAIN?
- An experiment is a procedural method of solving a scientific problem or answering a scientific question. An ideal experiment should contain two variables namely: independent variable and dependent variable.
- Dependent variable: This is the variable that the experimenter measures in the experiment. The dependent variable responds to changes made to the independent variable.
- Independent variable: This is the variable that is manipulated in an experiment in order to bring about a response.
In the experiment conducted by the student in this question in order to determine how the temperature of water affects the time for sugar to dissolve. The independent variable is the DIFFERENT TEMPERATURE OF WATER while the dependent variable is the TIME TAKEN FOR SUGAR TO DISSOLVE.
N.B: An experiment should have only one independent variable and all other variables should be kept constant. This is to have a reliable result.
- However, this student used two independent variables (temperature and amount of water) for the experiment, which is wrong for the experimental design.
Therefore, the fact that the student changed more than one independent variable is wrong for the experimental design.
Learn more: brainly.com/question/967776
There are 20.8 moles of propanol
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
1.2 x 10⁵ molecules of propanol
