Which metals are so reactive that they are never found as uncombined elements in nature?

A. alkaline earth metals

B. alkali metals

C. rare earth metals

D. transition metals

Answers

Answer 1
B

This element is rare and it reacts very quickly to other elements

Related Questions

What periodic element is from france

Answers

Answer:

Francium

Explanation:

I really don't know how to explain this

Francium there is no explanation!

please help me ill give brainiest

Answers

Your reactants are on the left side and your product is on the right side
Reaction on the left product on the right

Why are lysosomes important?

Answers

When a cell is beyond repair, lysosomes help it to self-destruct in a process called apoptosis.

Answer: A lysosome is a membrane-bound cell organelle that contains digestive enzymes soooo. They break down excess or worn out cell parts, they may be used to destroy invading viruses and bacteria. If the cell is damaged beyond repair, lysosomes can help it to self-destruct in a process called programmed cell death, or apoptosis.

Explanation: So that's why it is important

HELP! A bone contains 6.25% of Carbon -14 it began with. How old is the bone ?

Answers

Answer:

6.25 yrs

Explanation:

6.25 years in total

What happens to the solar energy absorbed by plants during photosynthesis?
A-It is recycled by plants and returned to the atmosphere.
B-It is converted into oxygen and glucose.
C-It is stored as heat within the plant for cellular functions.
D-It is transformed into chemical energy.

Answers

Answer:

b- It is converted into oxygen and glucose.

Explanation:

B the plant takes in sunlight to create its own food source converting sunlight into oxygen and glucose during photosynthesis

What is density?


1. a measure of salinity


2. the weight of water


3. the amount per unit volume of a particular material


4. the amount of salt in water

Answers

Answer: 3, the amount per unit volume of a particular material
3 is the correct answer

Ten of the sixteen nonmetals are _____ at room temperature.


A. solids

B. gases

C. alloys

D. liquids

Answers

A) because 10 non-metals are solids: Important solid non-metals are: Boron (B), Carbon (C), Silicon (Si), Phosphorus (P), Arsenic (As), Sulphur (S), Iodine (I). 11 non-metals are gases: These are: Hydrogen (H), Nitrogen (N), Oxygen (O), Fluorine (F), Neon (Ne), Chlorine (Cl), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).

can anyone help me with the question?? “Is the ending substance the same substance as the colorless liquid and why”

Answers

Answer:

It's Gas.

Explanation:

It would be gas. The chemist mixed it and the atoms evaporated.

A tool might be made of an alloy because the alloy _____.


A. occurs naturally

B. resists rust

C. can bend easily

D. is softer

Answers

I assume the answer is: A
~Hello Wonderful Person~

Your answer is:

B. Resists rust.

A tool might be made of an alloy because the alloy resists rust.

Why?

Iron is a great building material but steel (an alloy made by adding small amounts of non-metallic carbon to iron) is stronger, harder, and rustproof. Aluminum is a very light metal but it's also very soft in its pure form.

Alloy steels have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in the coinage.

____________________________________________________________

Hope this helps!

⊕If this answer does not answer your question or displeases you, tell me in the comments and I will try to find the right answer and replace it ASAP. Thank you.⊕

Have a good day.

explain why the sun appers to be the brightest star in the sky. relate your explanation with an example such as street lights. this is science

Answers

Answer:

The sun is a star but It is the brightest in the sky because it is the closest star to earth.

I don't know how to compare it to street lights though...

Explanation:

Please help!

Geologists determine the hardness of a mineral using the Mohs scale of hardness. Why is it important for geologists to be able to do these tests in the field?

Answers

Answer:

To help determine what type of rock it is

Explanation:

Geologists can use information such as color, hardness, grain size, texture and other aspects of the rock to figure out the classification of a rock. for example, a light blue rock with no visible grain that is translucent and has a hardness of 9 is most likely going to be a saphire. hope this helps!!!!

the hardness would help geologists identify what kind of mineral it is based on the Mohs scale

Which of the following is a metal?


A. nitrogen

B. calcium

C. sulfur

D. carbon

Answers

Answer:  Calcium

Explanation: The chemical element Calcium (Ca), atomic number 20, is the fifth element and the third most abundant metal in the earth's crust. The metal is trimorphic, harder than sodium, but softer than aluminium.

Hope this helps. pls mark me brainliest :)

The answer is calcium


because it is in group 2 which makes it an alkaline earth metal and a powerful reducing agent that loves to react with nonmetals especially powerful oxidizing agents like fluorine and chlorine.

Plz help!
How does the path of a river change over time? (describe the process)

Answers

All rivers erode the land over which they pass rendering a more gradual radiant to surrounding areas overtime.

Answer:

All rivers naturally change their path over time, but this one forms meanders

Explanation:

When you stand next to a river, its path doesn't seem to move.

All rivers naturally change their path over time, but this one forms meanders  at an especially fast rate, due to the speed of the water, the amount of sediment in it, and the surrounding landscape.

Identify the most abundant cell type making up the epidermis and provide evidence to support your claim

Answers

Answer: A keratinocyte

Explanation: A keratinocyte is the primary cell type (about 90%) within the epidermis which is the outermost layer of the skin. The alternate names for keratinocytes are basal cells since they are found in the basal layer (the stratum basale) of the skin.

Danny is trying to figure out how fast sugar crystals can dissolve in water. He has already tested crystals of table sugar by just pouring packets of sugar into a bowl of room-temperature water.

Which should Danny try next if he wants to make the sugar dissolve slower?
A.
stir the water
B.
use larger crystals
C.
heat the water
D.
all of these

Answers

Answer:

B

Explanation:

B

Explanation : say you have a chunk of Ice if it’s a small piece it will most likely dissolve within 2-7mins depending on the size but if it’s a bigger piece it will probably take 15-30 mins depending on the size

please help i dont understand this

Answers

I don’t understand either
Thabkdmdgkkdjdndmdmfid

PLEASE HELP MEEEE THIS IS ABOUT BODY SYSTEMS

Answers

Yeah just look it up use quizlet
It is on the Quizlet app

The most common way humans contribute to the extinction of organisms is by

rotation of crops.

use of fertilizers.

destruction of habitat.

introduction of competing species.

Answers

Destruction of habit because you are destroying their home and comfort and their preys home to do theirs no food

The most common way humans contribute to the extinction of organisms is by destroying their habitats. By destroying the natural habitats of organism we are leading them to point where they cant survive.

What is extinction ?

Extinction of an organism is the gradual disappearance of the entire species of that organism due to natural calamities, human activities or, spreading diseases.

Human activities are the main culprits of the devastation of organisms and their habitats. Humans destroy the natural habitats of plants and animals for their selfish purposes.

Animals then starve and they are not fit to survive in other places which are entirely different from their natural habitat. Therefore, if these activities continues they will extinct.

Find more on extinction?

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Which of these can be combined to make a mixture?

a. solid and a liquid
b. two solids
c. two liquids

Answers

Two liquids is the correct answer

Answer:

c

Explanation:

you cant mix a rock and a rock together and expect to get a mixture

and you cant mix a rock and water and expect them to mix

so its on logical that it is two liquids

Which elements do not normally form compounds?


A. nonmetals

B. alkali metals

C. metalloids

D. noble gases

Answers

I believe the answer is B:noble gases I’m glad to help

Answer:

D. noble gases

Explanation:

l hope it helps

The density of Mg is 1.74g/cm3. The density of strontium is 2.60g/cm3. What would you expect the density of Ca to be?

Answers

Answer:

1.61 g/cm³.

Explanation:

What is one advantage of developing energy-efficient technologies?

Answers

Answer:

it's simple

Explanation:

For residential buildings, a whole-house approach using a cost-effectiveness criterion can result in savings of 50 percent or more in heating and cooling and 30–40 percent reductions in total energy use.

I hope you understand have a great day :3

One advantage of developing energy-efficient technologies, would be less waisted money on electricity.

PLEEASEE HELP ITS PAST DUE AND IM GIVING BRAINLIEST

Which process is an example of a physical change?

a. wood burning in a camp fire
b. iron rusting on a bicycle chain
c. ice melting after a snow storm
d. milk souring because it is old

Answers

Answer:

c or d

Explanation:

i dont know which one but it's one of those

Why do you think it’s useful for scientists to classify matter? In other words, why do you think scientists need to identify something as a pure substance? Why do you think they need to know if something is a compound or an element?

Answers

Answer:

They need to know

Explanation:

Because if we didn't know that something was a compound of an element we could either blow ourselves up when we are mixing them or when we are looking for something bad between the compound and we don't know its a compound how do we fix it

Classifying substances as elements or compounds helps us to understand their properties.

Matter is anything that has mass and occupy space. There are several substances in the universe and all of them are composed of matter. It is necessary to classify matter for reference purposes. When we classify matter then it is possible to refer to substances under specific classes.

A pure substance contains only one kind of matter. It is necessary to classify something as a pure substance so that it is we can know if it contains one type of matter or different types of matter.

It is necessary for scientists to classify something as element or compound in order to understand its properties. Elements and compounds are pure substances.

Learn more: https://brainly.com/question/13516179

In which ocean zone does a reef most likely thrive?

Answers

tropical and subtropical zones

What element glows in sign's when excited

Answers

Answer:

The element that glows in signs is xenon.

Explanation:

Xenon is a chemical element with the symbol Xe and atomic number 54. It is a colorless, dense, odorless noble gas found in Earth's atmosphere in trace amounts. Xenon is used in flash lamps, arc lamps, and as a general anesthetic. Xenon emits a blue or lavenderish glow when excited by electrical discharge, it emits a band of emission lines that span the visual spectrum, but the most intense lines occur in the region of blue light, producing the coloration.

The is the part of the electrical circuit along which electricity travels.
_________ ________________ is a circular path of electric current, from the source of energy and back.

The flow of electric charge through a path is called an

A form of energy is _________________.

The ___________ uses electricity from the source.

Please help for brainlest

Answers

Answer:

The conductor runs a circular path from the power source, through the resistor, and back to the power source. The power source moves the existing electrons in the conductor around the circuit. This is called a current. Electrons move through a wire from the negative end to the positive end.

Explanation:

this help?

]Why is permeable soil best for plants that need a lot of drainage?

Water fills this type of soil.
Water dries up in this type of soil.
Water flows through this type of soil.
Water pools on top of this type of soil.

Answers

It is water flows through this type of soil
Answer 3 is the correct answer

What kinds of anthropogenic activities produce acid rain?

Answers

Answer:

Rotting vegetation and erupting volcanoes release some chemicals that can cause acid rain, but most acid rain is a product of human activities. The biggest sources are coal-burning power plants, factories, and automobiles.

Answer:

coal and oil power plants and automobiles

Explanation:

a) monday & thursday

b) wednesday & saturday

c) tuesday & saturday

d) saturday & sunday

Answers

Answer: b

Explanation: 5*2

Answer : should be B
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