Answer:
a) Measurements have a good precision.
Explanation:
Accuracy is the proximity of the data to the value considered as real, in this situation we do not know the real value and we do not know if the data is accurate or not, so we can discard options b and d.
Now, precision is the proximity of the data obtained among themselves and that is what we can observe, so the appropriate answer is the option a.
Some examples of physical changes are:
Breaking a glass
Chopping wood
Tearing paper
Mixing sand and water
Melting an ice cube
These all are physical changes because the composition of the matter does not change.
Answer:
Controlling the environment is the most key procedures for getting good results.
Explanation:
The control environment for an experiment is the essential part for getting good results. In control environment, there is no or less chances of disruption
from the external environment which can cause the results of the data more acceptable. So the scientists prefers laboratory for performing experiment as compared to outer environment. So in my opinion for getting better results, the control environment is the most necessary experimental procedure.
Answer:
gold and copper
Explanation:
but I think there is 1 more
Atomic radius
Explanation:
A decrease in moving from the bottom of Group 3 to the top of the group shows an increase in trend from top to bottom.
The atomic radius of elements increases from top to bottom and decreases from the bottom to the top.
The elements in group 3 are B, Al , Ga, In and Tl
- Atomic radius is taken as half of the inter-nuclear distance between two covalently bonded atoms of non-metallic elements or half of the distance between two nuclei in the solid state of metals.
- Downs a group from top to bottom, atomic radii increases progressively due to successive shells being added.
- This compensates for the size reducing effect of the increased nuclear charge.
learn more:
Atomic radii brainly.com/question/5048216
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