Which best describes the purpose of a controlled experiment?
to make sure the results of the experiment support the hypothesis
to prevent a dangerous condition resulting from a reaction
to examine whether one variable causes a change in another
to prevent an undesired change in a variable

Answer:

A population is a group of organisms belonging to the same species that live in the same area and interact with one another.

Explanation:

Levels of Ecological Organization

Level # 2. Population:

Level # 3. Community:

Level # 4. Ecosystem:

Level # 5. Biome:

Level # 6. Biosphere:

Given to us is the Reaction of Aluminium metal with Chlorine gas . That is ,

[tex]\boxed{\red{\bf \underset{\blue{Aluminium}}{2Al(s)}+\underset{\blue{Chlorine}}{3Cl_2(g)}\longrightarrow \underset{\blue{Aluminium\: chloride}}{2AlCl_3}}}[/tex]

Now Mass of 1 mole aluminium = 27g . So mass of 2 moles of it would be 27×2 g = 54g .

Also , Mass of 1 mole of chlorine gas = 35.5 g . So mass of 2 Atoms will be 71g . And mass of 3 moles of atom will be 71 × 3g = 213g .

Now , use unitary method ;

213 g of Chlorine reacts with 54g of Aluminium.

1 g of Chlorine will react with [tex]\sf\dfrac{54g}{213g}[/tex] of Aluminium.

Hence 52.9 g of Chlorine will react with [tex]\sf \dfrac{54}{213}\times52.9g[/tex]=[tex]\bf 13.41g[/tex] of Aluminium.

Answer:

it is second one

Explanation:

thanks

The Rutherford experiment rose above Thompson's Model 1911 with his gold-foil experiment. He designed an experiment to use the alpha particles created by a radioactive element as probes. Hope this helps you.

Answer:

A  consumer is an organism that eats other organisms to gain energy; it is also called  a heterotroph.

A  producer is an organism that makes its own food; it is also called  an autotroph.

A  decomposer is an organism that breaks down waste and dead organisms.

Explanation:

Green plants are examples of autotrophs that make their own food by photosynthesis - they don't rely on other organisms to provide them with energy.

In contrast, many organisms rely on other organisms as an energy source. These organisms are called consumers or heterotrophs. They consume producers and other consumers.

Decomposers such as some fungi, bacteria, and certain insects break down dead or decaying biological material and recycle the nutrients back into the soil.  

Answer:consumer a heterotroph producer an autotroph decomposer

Explanation:

Answer:

Explanation:

In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays.

I tried, I hope it helps :)

Answer:

The climate of any particular place is influenced by a host of interacting factors. These include latitude, elevation, nearby water, ocean currents, topography, vegetation, and prevailing winds.

Explanation:

those are what does not affect climate

Answer:

kilometers.........

Explanation:

where there are negative or positive ions

Explanation:

Protons

Each element has an atomic number. The atomic numbers are listed along with the names and symbols of the elements on the inside cover of the text. The atomic number equals the charge on the nucleus. It therefore also equals the number of protons in the nucleus and also equals numerically the number of electrons in the neutral atom. The atomic number has the symbol Z.

Different elements have different atomic numbers; therefore, atoms of different elements contain different numbers of protons (and electrons). Oxygen has the atomic number 8; its atoms contain 8 protons and 8 electrons. Uranium has the atomic number 92; its atoms contain 92 protons and 92 electrons.

The relationship between atomic number and the number of protons or electrons can be stated as follows:

Atomic number= number of protons per atom= number of electrons per neutral atom

B. Mass Number Equals Protons plus Neutrons

Each atom also has a mass number, denoted by the symbol A. The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. In other words, the number of neutrons in any atom is its mass number minus its atomic number.

Number of neutrons = mass number - atomic number

or

Mass number = number of protons + number of neutrons

The atomic number and the mass number of an atom of an element can be shown by writing, in front of the symbol of the element, the mass number as a superscript and the atomic number as a subscript:

mass number

atomic numberSymbol of elementorA

ZX

For example, an atom of gold (symbol Au), with an atomic number 79 and mass number of 196 is denoted as:

196

79Au

C. Isotopes

Although all atoms of a given element must have the same atomic number, they need not all have the same mass number. For example, some atoms of carbon (atomic number 6) have a mass number of 12, others have a mass number of 13, and still others have a mass number of 14. These different kinds of the same element are called isotopes. Isotopes are atoms that have the same atomic number (and are therefore of the same element) but different mass numbers. The composition of atoms of the naturally occurring isotopes of carbon are shown in Table 4.2.

TABLE 4.2 The naturally occurring isotopes of carbonIsotopeProtonsElectronsNeutrons12

6C66613

6C66714

6C668

The various isotopes of an element can be designated by using superscripts and subscripts to show the mass number and the atomic number. They can also be identified by the name of the element with the mass number of the particular isotope. For example, as an alternative to

12

6C,13

6C,and14

6C

we can write carbon-12, carbon-13, and carbon-14.

About 350 isotopes occur naturally on Earth, and another 1500 have been produced artificially. The isotopes of a given element are by no means equally abundant. For example, 98.89% of all carbon occurring in nature is carbon-12, 1.11% is carbon-13, and only a trace is carbon-14. Some elements have only one naturally occurring isotope. Table 4.3 lists the naturally occurring isotopes of several common elements, along with their relative abundance.

TABLE 4.3 Relative abundance of naturally occurring isotopes of several elementsIsotopeAbundance (%)hydrogen-199.985hydrogen-20.015hydrogen-3tracecarbon-1298.89carbon-131.11carbon-14tracenitrogen-1499.63nitrogen-150.37 oxygen-1699.76oxygen-170.037oxygen-180.204IsotopeAbundance (%)silicon-2892.21silicon-294.70silicon-303.09chlorine-3575.53chlorine-3724.47phosphorus-31100iron-545.82iron-5696.66iron-572.19iron-580.33 aluminum-27100

Answer

There is much more friction on the rough surface that there is on the smooth surface.

Answer:

I believe that in H-C≡N, Nitrogen has 4 bonding electrons and 2 non-bonding electrons.

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Explanation:

Answer:

Depends on if the atoms have the same amount of atomic mass and if they have the same amount of ions, or none at all.

Explanation:

They can be the same atom, but if they don't have the same amount of protons, electrons, and neutrons, they aren't identical.

This problem is providing information about the states of matter and a given diagram showing a molecular arrangement it has. Thus, we can start off by analyzing the attached file, which shows molecular arrangements and movements each state exhibits.

Solids are quite organized so that they are able to form molecular networks in which molecules vibrate but do not displace anywhere. Liquid molecules are close enough to have small movements and vibrations but are not able to form any organized network.

Gases, however, exhibit no molecular organization but large movements inside the container whose walls the gas constantly crash against. Plasma do not have any order neither yet it contains ions.

In such a way, since the given diagram do not have any apparent order or ion, we infer this is about a gas that moves into the container and crash against its walls.

Learn more:

Answer:

Explanation:

moles

bonding

balancing equations

and set ups

Answer:Physical changes involve states of matter and energy. No new substance is created during a physical change, although the matter takes a different form. The size, shape, and color of matter may change. Physical changes occur when substances are mixed but don't chemically react.

Explanation:

Answer:

omggggggggg that is sooo confusing what grade are you in?

Answer:

WTH? That is WOW....-_-

Answer:

wow

Explanation:

wow

Answer:

D. potential energy

Explanation:

Answer:

C.

Explanation:

The movement of the bow is Kinetic Energy.

Answer: C. Kinetic energy to sound energy

Explanation: The vibration of the string is kinetic energy that transforms into sound energy.

Answer:

Photosynthesis in plants converts solar energy into chemical energy using electrons and protons from water. ... In the energy-transduction reactions, solar energy is converted into chemical energy in the form of two energy-transporting molecules, ATP and NADPH.

Answer:

light energy to chemical energy :]

Explanation:

Answer:

i feel like the answer is A

Answer:

1. 1166.2

2. 2076

3. 1336. 8

4. 733.04

5. 1834.5

6. 556.6

7. - 410.6

8. 836.4

Explanation:

1.9 x 103 =928

Answer:

R=0.0564g K2SO4

Answer:

kg, m^3, kg/m^3

Explanation:

the SI units for these are:

mass: kilogram

volume: cubic meter

density: kilogram per cubic meter

Answer:

b is the answer

Explanation:

non metals are not shiny, brittle, unmalleable, and are poor conductors of thermal energy and electrical current.

A nonmetal is brittle, dull, and low in density.  

• Non-metals refer to the elements that produce negative ions by gaining or accepting electrons. The non-metals generally possess 4, 5, 6, or 7 electrons in their valence shell. The non-metals are those, which are devoid of all the metallic properties.  

• The non-metals in their solids-state are brittle, thus, they lack ductility and malleability exhibited by the metals.  

• The non-metals are not shiny like metals, they are dull in color.  

• The non-metals seem to possess low density, primarily as non-metals seem to prevail either in a liquid or solid-state. The non-metals lack the dense and closed packing in the lattice, which is seen in metals.  

Thus, non-metals are brittle, dull, and low in density.  

To know more about:

https://brainly.com/question/17811524

Answer:

Explanation:

The charge on the ion is 24 protons - 22 electrons = 2+

The element is Chromium (number 24 on the periodic table).

Cr^2+