A rock is an (blank) of minerals.


I don't get this at all.

Answer:

0.25

Explanation:

Answer:

.59

Explanation:

Answer:

B

Explanation:

i think with exothermic reactions heat is released

this is what i looked up

hope this helps i took chem last year and think this is what i learned

Considering the definition of exothermic and endothermic reactions, the correct answer is second option: the reaction is endothermic.

Energy is the ability to do work or to produce heat.

Remembering that chemical reactions involve a reorganization of atoms between substances with breaking or formation of chemical bonds, this formation or breaking of chemical bonds is accompanied by changes in the energy of the system.

Chemical reactions that release heat are called exothermic. That is, an exothermic reaction is one where energy flows out of the system.

So, at room temperature, the heat released by a chemical reaction is enough to cause a rise in temperature.

An endothermic reaction is one that requires heat to take place. In other words, a chemical reaction is endothermic when it absorbs energy from the environment.

In this case, the heat is transferred from the outside to the inside of the system. By absorbing heat, the effect of an endothermic reaction is to lower the temperature.

When ammonium chloride is dissolved in water, the beaker gets cold. That means the system is absorbing heat from the surrounding and the temperature does down.

So, the correct answer is second option: the reaction is endothermic.

Learn more about endothermic and exothermic reactions:

Answer:

In the chapters that follow, we will provide the temperature of the stars we are describing, and this section tells you how those temperatures are determined from the colors of light the stars give off. Hubble Space Telescope image of the Sagittarius Star Cloud. The image shows many stars of various colors, white, blue, red and yellow spread over a black background. The most common star colors in this image are red and yellow. Figure 1: Sagittarius Star Cloud. This image, which was taken by the Hubble Space Telescope, shows stars in the direction toward the center of the Milky Way Galaxy. The bright stars glitter like colored jewels on a black velvet background. The color of a star indicates its temperature. Blue-white stars are much hotter than the Sun, whereas red stars are cooler. On average, the stars in this field are at a distance of about 25,000 light-years (which means it takes light 25,000 years to traverse the distance from them to us) and the width of the field is about 13.3 light-years. (credit: Hubble Heritage Team (AURA/STScI/NASA))

Color and Temperature

As we learned in The Electromagnetic Spectrum section, Wien’s law relates stellar color to stellar temperature. Blue colors dominate the visible light output of very hot stars (with much additional radiation in the ultraviolet). On the other hand, cool stars emit most of their visible light energy at red wavelengths (with more radiation coming off in the infrared) (Table 1). The color of a star therefore provides a measure of its intrinsic or true surface temperature (apart from the effects of reddening by interstellar dust, which will be discussed in Between the Stars: Gas and Dust in Space). Color does not depend on the distance to the object. This should be familiar to you from everyday experience. The color of a traffic signal, for example, appears the same no matter how far away it is. If we could somehow take a star, observe it, and then move it much farther away, its apparent brightness (magnitude) would change. But this change in brightness is the same for all wavelengths, and so its color would remain the same. Table 1. Example Star Colors and Corresponding Approximate Temperatures

Star Color Approximate Temperature Example

Blue 25,000 K Spica

White 10,000 K Vega

Yellow 6000 K Sun

Orange 4000 K Aldebaran

Red 3000 K Betelgeuse

Go to this interactive simulation from the University of Colorado to see the color of a star changing as the temperature is changed. The hottest stars have temperatures of over 40,000 K, and the coolest stars have temperatures of about 2000 K. Our Sun’s surface temperature is about 6000 K; its peak wavelength color is a slightly greenish-yellow. In space, the Sun would look white, shining with about equal amounts of reddish and bluish wavelengths of light. It looks somewhat yellow as seen from Earth’s surface because our planet’s nitrogen molecules scatter some of the shorter (i.e., blue) wavelengths out of the beams of sunlight that reach us, leaving more long wavelength light behind. This also explains why the sky is blue: the blue sky is sunlight scattered by Earth’s atmosphere.

Color Indices

In order to specify the exact color of a star, astronomers normally measure a star’s apparent brightness through filters, each of which transmits only the light from a particular narrow band of wavelengths (colors). A crude example of a filter in everyday life is a green-colored, plastic, soft drink bottle, which, when held in front of your eyes, lets only the green colors of light through. One commonly used set of filters in astronomy measures stellar brightness at three wavelengths corresponding to ultraviolet, blue, and yellow light. The filters are named: U (ultraviolet), B (blue), and V (visual, for yellow). These filters transmit light near the wavelengths of 360 nanometers (nm), 420 nm, and 540 nm, respectively. The brightness measured through each filter is usually expressed in magnitudes. The difference between any two of these magnitudes—say, between the blue and the visual magnitudes (B–V)—is called a color index. By agreement among astronomers, the ultraviolet, blue, and visual magnitudes of the UBV system are adjusted to give a color index of 0 to a star with a surface temperature of about 10,000 K, such as Vega. The B–V color indexes of stars range from −0.4 for the bluest stars, with temperatures of about 40,000 K, to +2.0 for the reddest stars, with temperatures of about 2000 K. The B–V index for the Sun is about +0.65. Note that, by convention, the B–V index is always the “bluer” minus the “redder” color. Why use a color index if it ultimately implies temperature? Because the brightness of a star through a filter is what astronomers actually measure, and we are always more comfortable when our statements have to do with measurable quantities.

Explanation:yw :P

Answer: Robert Millikan

Explanation: Robert Millikan was the first person to perform the oil drop experiment. It was done many centuries ago. Hope this helps you!

Answer:

c

Explanation:

if you need explanation, ask freely

Answer:

16 oz

Explanation:

please mark as brainlist answers

Answer:

They do this so that water will diffuse into the vegetables and keep them plump and allow them to keep their look of freshness. 7. Roads are sometimes salted to melt ice.

Explanation:

1. A ➡️ Metals

2. B ➡️ Metalloids

3. C ➡️ Non-metals

4. D- Column ➡️ Group/Family

5. E- Row ➡️ Period

6. F ➡️ Halogens

7. G ➡️ Noble gases

Explanation:

The Periodic Table is known to be an array of chemical elements that are organized in order of their increasing atomic number. That arrangement gives a recurring pattern known as the periodic law in their properties.

Periods are found in the horizontal rows (across) the periodic table, while groups are found in the vertical columns (down) the table.

The Periodic Table was discovered by D.I Mendeleev.

Given parameters:

mass of an empty beaker = 65gm

mass of the beaker and water = 165gm

volume of water = 100cm³

Unknown:

Density of water  = ?

Solution:

Density is the mass per unit volume of a substance;

           Density  = [tex]\frac{mass}{volume}[/tex]

To find the mass of the water ;

   Mass of water  = Mass of beaker and water - mass of an empty beaker

                            = 165g - 65g

                           = 100g

So input parameters and solve;

         Density  =  [tex]\frac{100g}{100cm^{3} }[/tex]  

         Density of the water in the beaker  = 1g/cm³

Answer:

A wave reflection interaction (reflected by the wall)

Explanation:

In a reflection, the propagating wave is bounced off the reflecting surface because the medium of the surface prevents the propagation of the wave through it, such that wave is redirected at an angle equal to the angle of incident on the reflecting surface

Reflection takes place with the different forms of waves, such as sound wave, water waves, and light wave

The objects around us are seen with the aid of reflection of light from a light source such that the reflected light enters our eyes after being reflected on the surface of the object, and the object is seen.

Answer:

reflection

Explanation:

its on edg.

Answer:

baking powder and baking soda

Explanation:

I know this from prior knowledge, also the graph shows the two with plus signs on vinegar, which means they both react to it. :)

Baking powder and baking soda

On the table they both have a "+" meaning a reaciton has occured.

Hope this helps, brainliest pls! :)

Answer:

An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons. The positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. ... The nucleus of an atom contains protons and neutrons.

Explanation:

i'm smart you are too in your own way.

Answer:

Many things, but i think a toaster...

Explanation:

Answer:

Protons and neutrons are found in the nucleus of an atom. They make up a majority of the mass of an atom. In fact, the mass number of an element is the sum of its protons and neutrons. Since protons have a positive charge and neutrons are neutral, the nucleus of an atom is electrically positive.

Explanation:

Answer:

An electron in the first shell has more energy than an electron in the second shell.

Explanation:

Answer:

the two major sources of energy for the rock cycle are also shown; the sun provides energy for surface processes such as weathering, erosion, and transport, and the Earth's internal heat provides energy for processes like subduction, melting, and metamorphism.

Answer:

Explanation:

Explain why the name 1-propene is incorrect what is the proper name for this molecule

The name 1-propene is incorrect because;

The proper name for this molecule is;

Propene otherwise known as propylene is simply propane with a double bond at the first carbon.

When we get to the alkenes where the naming of organic compounds becomes more complex, the numbering system is used to indicate the position of the bonds.

With propene, there are three carbon atoms and the double bond will always appear in between two of the carbon atoms.

So, it is not important to use numbers to show that the carbon is at the first carbon. This becomes necessary from the next compound, butene, where there are more carbons.

Learn more here:

https://brainly.com/question/20359812

Answer:

True. Ripening of a banana is a chemical change

Answer:

it helps the area develop and help the animals adapt

Explanation:

im new so i hope this helps

Answer:

1) 5 protons, 2) 5, 3) boron, 4) 6 Neutrons, 5) 10.811 ≈ 11, 6) Boron-9

Answer:

A

Explanation:

Curly Hair

The number of particles : 2.75 x 10²¹

A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12  

1 mole = 6.02.10²³ particles  

[tex]\tt n=\dfrac{N}{N_o}[/tex]

N = number of particles  

No = Avogadro number (6.02.10²³)  

n = number of moles  

While the number of moles can also be obtained by dividing the mass (in grams) with the molar mass of element or molecule  

0.75 gram sample of Calcium Nitrate; Ca(NO₃)₂

MW of Ca(NO₃)₂ : 164.09 g/mol

[tex]\tt mol~Ca(NO_3)_2=\dfrac{0.75}{164.09}=0.00457[/tex]

The number of particles

[tex]\tt N=n\times N_o\\\\N=0.00457\times 6.02\times 10^{23}=2.75\times 10^{21}[/tex]

Answer:

No

Explanation:

I do not know

Explanation:

No because when it was formed it was a rocky lava wasteland

Answer:

Iron have 26 atomic and sodium have 11 atomic

Explanation:

The sodium is a non-transition metal. Its melting point is low and boiling points and is a soft metal, whereas iron is a transition metal with very high melting and boiling points, It is a hard metal.

The term transition metal is defined as any of various metallic elements such as chromium, iron, and nickel that have valence electrons in two shells instead of only one.

Between the s-block and p-block elements in the periodic table are transition metals. As a result, they are known as d-block elements.

Sodium is soft, has a much lower melting point than water, and reacts with it violently, producing heat and hydrogen or even exploding. Additionally, sodium and water react to create a hazardous compound.

Thus, these are difference between the properties of sodium and iron.

To learn more about transition element, follow the link;

https://brainly.com/question/1948991

#SPJ2

Answer:

and the last name then select a City the solution if they are getting elimination method if I can tell u that is telling you about me to this email and delete this email and any attachments may contain confidential information and rupees hundred years ago the pair in the solution if I can tell you my story of my teacher not respond please ask me to this email and any attachments is intended only for the independence of Bangladesh and what is the correct answer is yes we have to come at your earliest convenience and what is the correct answer

Answer:

If you are asking to suggest a method to preserve the extinction of this species of pigeon then

1. Governments should derive a law that will prevent hunting of these pigeons.

2. These pigeons should be given a place in sanctuaries with hospitable habitat made available.

3. If someone sees a bird of this kind care should be taken not to harm it intentionally or accidentally.

4. Breeding this type of Birds should be Promoted to increase their number

Answer:

is it a research work?

Explanation:

if it is first u write about what is a climate what r due to climatic changes

Answer:

《<☆HOPE IT WILL HELP YOU 》>☆

Explanation:

Dealing with the problem by

Never lose your hope you're cofidance your power

Always take dlessing or suggeation from the elder or your parent

•●○Please mark my ans as BRAIN LIST○●•

Answer:

sugar

Explanation:

because sugar dissolves

in water, while flower    because it is insoluble

Answer:

It's actually C

Explanation:

The Ice's mass was never destroyed, just converted therefore it would be C, which states the mass never disappeared, just changed to water.