CHEMISTRY
MIDDLE SCHOOL

Answer:

Answer:

Explanation: The respiratory system increases gas exchange, and the circulatory system circulates blood faster to deliver oxygen to muscles.

MIDDLE SCHOOL

A student measures the frequency of a wave as 2 waves/second, and the wavelength as 40 cm/wave. Use the velocity equation (v = f × λ) to calculate the speed of the wave. Show your work and include units.

The speed of the wave will be "80 m/s".

Given values are:

- Frequency, f = 2
- Wavelength, λ = 40

The speed of the wave:

→

or,

→

By putting the values, we get

Thus the solution above is correct.

Learn more about waves here:

brainly.com/question/17615600

V = 2*40

V= 80 m/s

I am not sure!!!

V= 80 m/s

I am not sure!!!

MIDDLE SCHOOL

What is the difference between the way historians and scientist think ?

Answer:

Historians think about how things have happened in the past and have been changing to the present day. Scientists, on the other hand, think about how the current physical universe can explain phenomena and situations that happen to society and how to improve current resources for the future.

Explanation:

The historian is an expert who tells and tells the story. So what does he do? He is dedicated to studying man from the earliest times to the present day. Among other things, historians allow us a better understanding of other civilizations and how ancient civilizations influence current civilizations.

The scientist, on the other hand, is a professional who performs a systematic activity to attain knowledge about something. Through the scientific method, it conducts research to understand clearly and accurately any fact pertaining to the physical, mathematical, chemical or social dimension of the environment or object studied, in order to solve a problem, explain a phenomenon and improve some resource so that we have a better life in the future.

Historians find proof in the past and scientists keep questioning and look at the future

MIDDLE SCHOOL

Sedimentary rocks that are made up of life pebbles and stones have a Coarse gained

Cool to know im not that interested, but cool to know

HIGH SCHOOL

The density of oxygen gas is 1.429 × 10–3 g/cm3 at standard conditions. What would be the percent error of the average of two separate experimental determinations measuring 1.112 × 10–3 g/cm3 and 1.069 × 10–3 g/cm3? (To solve this problem, average the two readings before calculating the percent error.)

Answer:

0.034%

Explanation:

First, let's calculated the average density (da) of the two experimental, which the sum of them divided by 2:

da = 1.090x10⁻³ g/cm³

The relative error is given by the difference of the correct value and the avarege, divided by the correct value:

e = 3.39x10⁻⁴ x 100%

e = 0.034%

MIDDLE SCHOOL

What is the expected product when l-propanol is oxidized? propanal

propanoic acid

propanone

propene

PLEASE EXPLAIN HOW YOU GOT YOUR ANSWER

Answer: propanal and propanoic acid

Explanation: first of all Oxidation of alcohol with mild oxidizing reagent PCC gives Carbonyl compounds and with strong oxidizing agent like CrO3 and kmno4 gives carboxylic acids.

And primary alcohol gives Aldehyde with mild oxidizing reagent and carboxylic acids with strong oxidizing agent.

And ketone is formed with secondary alcohol by both mild and strong Oxidizing agent.

Here our compound is primary alcohol hence we will get propanal and propanoic acid depending on type of Oxidizing agent

Answer:

propanoic acid

Explanation:

One of the properties of alkanols is the fact that they can be oxidized to various products depending on the structure of the alkanol.

A primary alkanol (such as 1-propanol) is oxidized to an alkanal and subsequently to an alkanoic acid.

A secondary alkanol is oxidized to an alkanone while a tertiary alkanol is not oxidized.

This implies that the final product of the oxidation of 1-propanol is propanoic acid as shown in the answer.

HIGH SCHOOL

A man drove his car through the Nevada desert one day when the temperature was over 100°F. When he started the trip, the gas station attendant found the tire to be 32 lb/in2. When he filled up with gas after crossing the desert, an attendant found the tire pressure to be 38 lb/in2. What is the best explanation for the increase in tire pressure? The road wear on the tire caused a decrease in volume and, therefore, an increase in tire pressure.

The temperature in the tire increased, causing an increased tire pressure.

The hot temperature caused the springs to expand, which allowed more weight to ride on the tires, thus causing more pressure inside.

The measurements of the pressure were inaccurate. The added weight of the gas caused the extra pressure in the tires.

The temperature in the tire increased, causing an increased tire pressure.

COLLEGE

Lactic acid is a common by-product of cellular respiration and is often said to cause the "burn" associated with strenuous activity. a 25.0-ml sample of 0.100 m lactic acid (hc3h5o3, pka 5 3.86) is titrated with 0.100 m naoh solution. calculate the ph after the addition of 0.0 ml, 4.0 ml, 8.0 ml, 12.5 ml, 20.0 ml, 24.0 ml, 24.5 ml, 24.9 ml, 25.0 ml, 25.1 ml, 26.0 ml, 28.0 ml, and 30.0 ml of the naoh. plot the results of your calculations as ph versus milliliters of naoh added.

I honestly dont know this one but ill ask my brother and he might know

MIDDLE SCHOOL

If the enthalpy value for a reaction is negative, what does that indicate about the reaction?

This indicates that the reaction is exothermic meaning that it releases heat/energy

COLLEGE

Which of the following statements explain why the van der Waals equation must be used to describe real gases? X. interactions between gas molecules reduces the temperature of the gas in the sample Y. the non-zero volumes of gas particles effectively decrease the amount of "empty space" between them Z. the molecular attractions between particles of gas decreases the pressure exerted by the gas

Answer:

Statements Y and Z.

Explanation:

The Van der Waals equation is the next one:

(1)

The ideal gas law is the following:

(2)

where n: is the moles of the gas, R: is the gas constant, T: is the temperature, P: is the measured pressure, V: is the volume of the container, and a and b: are measured constants for a specific gas.

As we can see from equation (1), the Van der Waals equation introduces two terms that correct the P and the V of the ideal gas equation (2), by the incorporation of the intermolecular interaction between the gases and the gases volume. The term an²/V² corrects the P of the ideal gas equation since the measured pressure is decreased by the attraction forces between the gases. The term nb corrects the V of the ideal gas equation, taking into account the volume occuppied by the gas in the total volume, which implies a reduction of the total space available for the gas molecules.

So, the correct statements are the Y and Z: the non-zero volumes of the gas particles effectively decrease the amount of "empty space" between them and the molecular attractions between gas particles decrease the pressure exerted by the gas.

Have a nice day!