Answer:
B. Spring balance - a device used for measuring the weight or force of gravity acting on an object.
Explanation:
A Force is any interaction that changes the motion or position of an obkpjectbthatbit is interacting with. Whenever there is an interaction between two objects, there is a force exerted by each of the objects on one themselves.
Forces are generally divided into contact forces and non-contact over field forces.
In contact forces, the two objects physically in contact with each other. Examples of contact forces are push or pull forces, frictional forces, tensional forces, spring forces, etc.
Non-contact forces are forces in which the two objects interacting do no need to be physically in contact with one another. Examples include, gravitational forces, magnetic forces, electrical forces, etc.
Instruments used in measuring forces are known as force gauges.
From the instruments listed above:
A. A ruler is an instrument used in measuring length
B. Spring balance is a device used for measuring the weight or force of gravity acting on an object.
C. A thermometer is an instrument used in measuring temperature
D. A windbvane is an instrument used in measuring wind direction.
The volume of 0.20 moles of helium at STP is 4.5 liters.
Explanation:
Given:
Number of moles = 0.20 moles
To Find:
The volume of Helium at STP =?
Solution:
According to ideal gas law
PV = nRT
where
P is pressure,
V is volume,
n is the number of moles
R is the gas constant, and
T is temperature in Kelvin.
The question already gives us the values for p and T
,because helium is at STP. This means that temperature is 273.15 K and pressure is 1 atm
.
We also already know the gas constant. In our case, we'll use the value of
0.08206 L atm/K mol since these units fit the units of our given values the best
On substituting these values we get



V = 4.5 Liters
The boiling point of hydrocarbons generally increases as the size of the molecules increases because more bonds are needs to be broken in larger organic molecules.
<h3>What are hydrocarbons?</h3>
Hydrocarbons are organic compounds which here composed of hydrogen and carbon alone.
Hydrocarbons are grouped into families or homologous series based on a reactive group known as the gincyiial group
The homologous series include
The boiling point generally increases as the size of the molecules increases because more bonds are needs to be broken in larger organic molecules.
Learn more about hydrocarbons at: brainly.com/question/3551546
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Answer:
the answer is atoms and molecules
Answer:
Find the list and explanation below.
Explanation:
Hydrochloric acid shortened as HCl is a harmful chemical when not handled properly. Four ways to avoid injury with hydrochloric acid include;
1. Dilution: It is advised to dilute the concentrated hydrochloric acid with a reasonable amount of water so that its corrosive effect can be significantly reduced.
2. Wear a laboratory coat: When working with hydrochloric acid in the laboratory it is always advised to wear a laboratory suit so as to ensure a minimal amount of harm in case of an accident or spillage with the acid.
3. Wear a face shield: It is also important that a face shield is worn while working with the acid to prevent contact with the eyes.
4. Wear a protective rubber glove: The rubber gloves would ensure that there is minimal contact of the acid with the hands.
Three steps to be taken in case of an accidental exposure include;
1. Medical Attention: In serious cases, such as in a case of ingesting the acid, urgent medical help should be sought for immediately.
2. Water: If there is contact with the skin or eye, a lot of water should be used on the affected area, and then medical help obtained.
3. Inhalation of fresh air: In a case whereby the hydrochloric acid was inhaled for a long time, the affected person should try to get some fresh air and if other effects are noticed, urgent medical attention should be gotten.