Answer:
5200 ppm
Explanation:
As per the definition, parts per million of a contaminant is a measure of the amount of mass of contaminant present per million amount of the solution. It is denoted by ppm.
Given in the question,
Water = 250 ml = 250 g
Lead = 1.30 g
So,
ppm of Lead = 
= 
= 5200 ppm
So, as calculated above, there is 5200 ppm of lead present in 250 ml of water.
Answer:
This question will be answered based on general understanding of how a controlled experiment should be:
The answer is: We must make sure we are testing/changing only one variable, and controling others
Explanation:
A controlled experiment is an experiment in which the independent variable is changed for a particular group called the EXPERIMENTAL group and unchanged for another group called the CONTROL group.
In a controlled experiment, only one variable should be tested while the others should be kept constant in order to have an effective result or outcome. This is the case in this question, the type of music or soil should be unchanged for each plant because the experimenter must make sure that he/she is testing/changing only one variable, and controling others.
Answer:
In my opinion, water is a compound.
Explanation:
Water is mixed from Oxygen(O) and Hydrogen(H) and they cannot be splitted.
Sorry if there any mistakes
Answer:
8.6g/cm³ (BRASS)
Explanation:
Given the following :
Mass of object = 86g
Volume of object = 10cm³
The density of an object is calculated using the formula :
Density(g/cm³) = mass(g) / volume(cm³)
Inputting our values :
Density = 86g / 10cm³
Density = 8.6g/cm³
According to the table provided, the object which corresponds to having a density of 8.6g/cm³ is BRASS
