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:
The number of proton of magnisium = 12
<span>Moles = 0.252
Molarity = 1.07
This question is badly worded. You're asking for moles and I suspect you really want molarity. The number of moles of ammonium chloride you have in the solution will remain constant regardless of the volume of the solution. However, the molarity of the solution will differ depending upon how concentrated it is. So I'll give you both the number of moles of ammonium chloride you have, and the molarity of the resulting solution. Please talk to your teacher if you're confused by the difference between moles and molarity.
The formula for ammonium chloride is NH4Cl. So let's calculate it's molar mass. Start by looking up the associated atomic weights.
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Atomic weight chlorine = 35.453
Molar mass NH4Cl = 14.0067 + 4 * 1.00794 + 35.453 = 53.49146 g/mol
Moles NH4Cl = 13.5 g / 53.49146 g/mol = 0.252376735 mol
Molarity is defined as moles per liter, so let's divide the number of moles we have by the volume in liters. So:
0.252376735 mol / 0.235 l = 1.073943551 M
Rounding to 3 significant figures gives: 0.252 moles, 1.07 molarity.</span>
The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons.
Answer: Q= -34.6 J
Explanation: Use Q= mc∆T
c for solid lead is equal to 0.159 J/g°C
Substitute the values:
=14.8 g(0.159J/g°C)(23.7°C-38.4 °C)
= 14.8 g(0.159J/g°C) ( -14.7°C)
= -34.6 J
Cancel out the following units: g and °C so the remaining unit is in J.
