
If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
The gas is ignited (I think) and combustion happens where the gasoline turns into gas (the state of being) and expands, pushing something and making the blades turn so
from stationary to explosive so potentioal to kenetic
Answer: 10
Explanation:
The detailed solution is contained in the image attached. The molar mass of hydrated and anhydrous salts are obtained and the number of moles of hydrated and hydrated salts are equated. The masses of hydrated and anhydrous salts are gives in the question and are simply substituted accordingly. This can now be used to obtain the number of molecules of water of crystallization as required in the question.
Answer:
Explanation:
In this chemistry lab, students investigate how to build and launch a simple rocket that uses hydrogen and oxygen gases that will be mixed to propel the rocket (large bulb plastic pipette). Students will understand the principles of combustion reactions, kinetics, stoichiometry of reactions, activation energy, explosive mixtures, rocketry, and different types of chemical reactions. Students will explore and determine the proportions of hydrogen and oxygen mixture that will achieve the best launch results. Students will compare the balanced chemical reaction of hydrogen and oxygen with their lab results; students should discover that the optimal distance occurs when the mixture of hydrogen and oxygen is two to one hydrogen, oxygen mixture ratio and this can be determined theoretically from the balanced chemical reaction equation. Students will perform the lab, collect data, and discuss, compare, and contrast their lab findings with the balanced chemical reaction equation. Students will present their structured inquiry investigations using a power-point presentation. Other groups along with the teacher will assess each group by using a provided rubric. Group assessments will be the deciding assessment for the final lab score. A follow up activity could investigate how NASA scientists launch real rockets into space and propose a procedure to investigate and collect data on a launching a heavier object at the school football field.
The density of magnesium will be 1.74 g/cm³ if 23.5 g of magnesium occupies 13.5 cm³
<h3>What is Density ?</h3>
Density is the measurement of how tightly a material is packed together.
It is defined as the mass per unit volume.
Given ;
- Mass = 23.5 g
- Volume = 13.5 cm³
Formula to calculate density ;
Density = mass / volume
=23.5 / 13.5 = 1.74 g/cm³
Hence, the density of magnesium will be 1.74 g/cm³ if 23.5 g of magnesium occupies 13.5 cm³.
Learn more about density here ;
brainly.com/question/15164682
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