1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Eduardwww [97]
3 years ago
15

How can scientists know what happened millions of years ago if no one was there to see it?​

Chemistry
1 answer:
xxMikexx [17]3 years ago
4 0

Answer:

In the 150 years since Darwin proposed the theory of evolution by natural selection, a mountain of evidence has accumulated ... How can you know what happened millions of years ago if no one was there to see it? Evidence and observation are the building blocks of all scientific inquiry; evolutionary science is no different

Explanation:

You might be interested in
Which statement best describes how an existing theory is often affected by the development of new technology?
grigory [225]

Answer: An existing theory is modified so that it can explain both the old and new observations.

Explanation:

4 0
3 years ago
What are the 6 things needed on a graph?
Furkat [3]
1. Always give your graph a title in the following form: "The dependence of (your dependent variable) on (your independent variable). <span><span>Let's say that you're doing a graph where you're studying the effect of temperature on the speed of a reaction. In this reaction, you're changing the temperature to known values, so the temperature is your independent variable. Because you don't know the speed of the reaction and speed depends on the temperature, the speed of the reaction is your dependent variable. As a result, the title of your graph will be "The dependence of reaction rate on temperature", or something like that.</span> 

 </span>2. The x-axis of a graph is always your independent variable and the y-axis is the dependent variable.<span>For the graph described above, temperature would be on the x-axis (the one on the bottom of the graph), and the reaction rate would be on the y-axis (the one on the side of the graph) 

 </span>3. Always label the x and y axes and give units.<span>Putting numbers on the x and y-axes is something that everybody always remembers to do (after all, how could you graph without showing the numbers?). However, people frequently forget to put a label on the axis that describes what those numbers are, and even more frequently forget to say what those units are. For example, if you're going to do a chart which uses temperature as the independent variable, you should write the word "temperature (degrees Celsius)" on that axis so people know what those numbers stand for. Otherwise, people won't know that you're talking about temperature, and even if they do, they might think you're talking about degrees Fahrenheit. 
 
</span>4. Always make a line graph<span><span>Never, ever make a bar graph when doing science stuff. Bar graphs are good for subjects where you're trying to break down a topic (such as gross national product) into it's parts. When you're doing graphs in science, line graphs are way more handy, because they tell you how one thing changes under the influence of some other variable. </span> 
 
</span><span>5. Never, EVER, connect the dots on your graph!Hey, if you're working with your little sister on one of those placemats at Denny's, you can connect the dots. When you're working in science, you never, ever connect the dots on a graph.Why? When you do an experiment, you always screw something up. Yeah, you. It's probably not a big mistake, and is frequently not something you have a lot of control over. However, when you do an experiment, many little things go wrong, and these little things add up. As a result, experimental data never makes a nice straight line. Instead, it makes a bunch of dots which kind of wiggle around a graph. This is normal, and will not affect your grade unless your teacher is a Nobel prize winner. However, you can't just pretend that your data is perfect, because it's not. Whenever you have the dots moving around a lot, we say that the data is noisy, because the thing you're looking for has a little bit of interference caused by normal experimental error.</span><span>To show that you're a clever young scientist, your best bet is to show that you KNOW your data is sometimes lousy. You do this by making a line (or curve) which seems to follow the data as well as possible, without actually connecting the dots. Doing this shows the trend that the data suggests, without depending too much on the noise. As long as your line (or curve) does a pretty good job of following the data, you should be A-OK. 

 </span>6. Make sure your data is graphed as large as possible in the space you've been given.<span><span>Let's face it, you don't like looking at little tiny graphs. Your teacher doesn't either. If you make large graphs, you'll find it's easier to see what you're doing, and your teacher will be lots happier.</span> 
 </span><span>So, those are the steps you need to follow if you're going to make a good graph in your chemistry class. I've included a couple of examples of good and bad graphs below so you know what these things are supposed to look like.</span>
5 0
3 years ago
Read 2 more answers
Whats the difference between Homogeneous and Hetrogeneuos?
irakobra [83]

Answer:

Homogeneous - With a uniform appearance

Heterogeneous - With visible differences in the mixture

Explanation:

Referring to mixtures, homogeneous looks the same throughout, while heterogeneous has particles or whatnot.  

Basically:

Homo means same

Hetero means different

6 0
3 years ago
The Hanunoo people of the Philippines have 92 words for rice, Arabs have 250 words for camel, and people in English-speaking cou
docker41 [41]

Answer:

The correct approach will be the "Linguistic-relativity hypothesis".

Explanation:

  • This theory can be defined as either the Hypothesis of Sapir-Whorf. This theory proposes whether our cognitive capabilities are influenced by languages as well as decide how we start behaving and communicate throughout society.  
  • Sapir Whorf explains these variations throughout the nature of human language throughout the manner a person understands the world.
3 0
3 years ago
1. Imagine you have a sealed 20.0 L balloon filled with helium gas at 750 mmHg in the
SVETLANKA909090 [29]

Answer:

17.6510 L

Explanation:

First we should get the number of moles of helium here by Boyle's law

PV=nRT

P=750/760= 0.9868 atm

T=25+273=298 kelvin

R= 0.08206

V= 20L

so

n=PV/RT

n=0.9868×20/0.08206×298

n=0.80707 mol

Then use the same law

V=0.80707×0.08206×263/0.9869=

17.6510L

SO THE VOLUME WILL BE 17.6510 L

6 0
2 years ago
Other questions:
  • When sugar is mixed with water, equilibrium is reached when __________?
    14·1 answer
  • Which of the following is a change from a less condensed to a more condensed state of matter?
    13·1 answer
  • What is the term?
    14·1 answer
  • WORTH 99 POINTS PLEASE ANSWER!!! The table shows the solubility of two substances in water at 20 °C. Solubility of Substances Ma
    10·2 answers
  • A gas has a pressure of 410 atm and a volume of 32 L. At what pressure would the volume of the gas change to 28L?
    6·1 answer
  • The amount of matter in a given space or volume
    8·2 answers
  • What is the molarity of a solution made by dissolving 14.8 g of ammonium hydroxide NH4OH, in enough water to make 250.0 mL of so
    5·1 answer
  • What do two different neutral isotopes of the same element have in common?
    6·1 answer
  • HELP ME PLS!! I FORGOT TO STUDY Which may result from an increase in friction?
    8·2 answers
  • The building blocks of DNA are like alphabet letters,
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!