can you always tell by looking at a substance if it is pure or not? ​

Answer:

2) a

3) c

explanation:

both gain from the relationship in number 2

while in number 3 one gains and one is hurt

Answer:

Eat healthy food  and exercise daily also undertake good healthcare

There are some special exercises that help to increase brain strength you can do them

Answer:

solid objects

cooler to warmer

sitting on a metal chair.

Explanation:

im correcr

If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion. If it loses an electron, it becomes positively charged and is known as a cation.

I looked it for you, hope that helped <3

Answer:

Chemical bonds are forces that hold elements together. it can be either covalent or ionic bonds that are these chemical bonds.

Answer:

C. the relative molecular mass of the compound

Explanation:

Like molecular formulas, empirical formulas are not unique and can describe a number of different chemical structures or isomers. To determine an empirical formula, the relative molecular mass of the composition of its elements can be used to mathematically determine their ratio.

Answer:

They are Weaker than a chemical

corrected by the one in the comment section

Answer: Yes, I think light can cause the plastic to melt, as long as the energy from the light is absorbed by the plastic.  

Explanation:

Visible light will not melt the plastic because the energy does not pass through the plastic, it reflects off ensuring that the plastic does not absorb the energy. X-ray light is transmitted through the plastic, unlike the visible light, but the energy still isn't absorbed by it. The infrared light is the only one left, it is absorbed by the plastic allowing it to change and melt the material, unlike the visible and x-ray lights.

The plastic will melt if the energy from the light is absorbed by the plastic.  

These are forms of electromagnetic waves which propagate through space

and carry electromagnetic radiant energy. Examples include:

Visible light and X-ray light won't melt the plastic as a result of the energy

not being absorbed whereas in the case of Infrared lights, the energy is

absorbed which will led to the melting of the plastic.

Read more about Electromagnetic radiation here https://brainly.com/question/1293367

Answer:

More freely moving than a solid

Explanation:

Answer:

chemical weathering

Explanation:

Chemical weathering is the process responsible for changing the composition of rocks.

Weathering is the process by which rocks are broken down into smaller or tiny pieces.

There are different types of weathering namely;

Chemical weathering is the type of weathering that changes the chemical composition of rocks.

Learn more about chemical weathering at: https://brainly.com/question/14426457

Yes, the ink can take in energy from the light, causing it to become visible.

Answer:yes it can

Explanation:

A: the ball in frame A had the highest velocity, and the ball in frame B has the highest kinetic energy

Answer:The crayosphere- it is the portion of the Earth's surface where water is in solid form for at least one month of the year..-has been shrinking in response to climate warming.The important outcome,however,is the change and the response the human social system (infrastructure,food ,water,recreation) will be have to that change...

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Answer:

50

Explanation:

mookie betts 50 is goated no cap

Answer:

The new estimates suggest that atmospheric oxygen levels have fallen by 0.7 percent over the past 800,000 years. The scientists concluded that oxygen sinks processes that removed oxygen from the air were about 1.7 percent larger than oxygen sources during this time.

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[tex] \huge \sf \underline \blue{Question} \colon[/tex]

When two clear substance combines, an insoluble solid is formed that settle downs as a ________.

[tex] \huge \sf \underline \blue{Answer} \colon[/tex]

When two clear substance combines, an insoluble solid is formed that settle downs as a precipitate.

→A precipitate is a substance to be deposited in solid form from a solution.

______________________________________

Answer:

BeO

Reaction of beryllium with air

However, powdered beryllium metal does burn in air to give a mixture of white beryllium oxide, BeO, and beryllium nitride, Be3N2. Beryllium oxide is more normally made by heating beryllium carbonate. 2Be(s) + O2(g) → 2BeO(s)

Answer:

An exothermic reaction is going to produce energy.

Explanation:

rAn exothermic reaction is going to release energy meaning that your ending product will be negative. However if it is an endothermic reaction, it is going to absorb energy/requires energy, and will have an ending product that is positive.

a) There are 19 electrons in a potassium atom. I don't really know how to explain it. I've been told that the number of protons and electrons are the same.

b) There are two electrons on the first shell, 8 on the second, 8 on the third, and 1 one on the fourth shell, which totals 19.

c) There is one electron in the valence shell.

d) I don't know what to do for this one. Sorry.

a) 19 electrons are present, the same number as the protons

b) [Ar] [tex]4s^{1}[/tex] (condensed)

c) theres one valence electron in a potassium atom

d) they could be heated

Answer:

Some benefits of genetic engineering in agriculture are increased crop yields, reduced costs for food or drug production, reduced need for pesticides, enhanced nutrient composition and food quality, resistance to pests and disease, greater food security, and medical benefits to the world's growing population.

Answer:

Valency is the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with

Answer:

[tex]\frac{140}{57}La -------->\frac{140}{58} Ce +\frac{0}{-1} \beta[/tex]

Explanation:

Beta emission occurs when a neutron is converted to a proton, an electron and a neutrino. This phenomenon reduces the neutron-proton ratio(N/P).

When a beta emission occurs, the mass number of the daughter nucleus is the same as that of the parent nucleus while the atomic number of the daughter nucleus increases by one unit.

We can see this explanation above in the reaction described in the answer section.

Answer:

a. 4KCN

Explanation:

Four is a coefficient found in the chemical formula 4KCN.

KCN is potassium cyanides.

 A coefficient is a number that is written before a chemical compound. It is usually used to balanced reaction expression.

Chemically such numbers indicate the number of moles or volume of that specie.

Since KCN is the only compound with 4 before it, so, the solution is KCN

Answer:

It is the sharing of electrons between atoms with an electronegativity difference below 1.7.

Explanation: Covalent bond is the bond which is formed with the sharing of the electrons between the two atoms which are taking part in the bond.

Answer: Covalent bond, in chemistry, the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons.

Explanation: A covalent bond forms when the bonded atoms have a lower total energy than that of widely separated atoms.

Answer:

no

Explanation:

the atomic number the just the number below the symbol of the element as well as proton number or electron number, however if u want to work out the neutron number you have do mass number (which is on the top of the symbol) substact atomic number/proton number

Answer:

Answer is flagella

Explanation:

I hope it's helpful!

As greenhouse gas emissions from human activities increase, they build up in the atmosphere and warm the climate, leading to many other changes around the world—in the atmosphere, on land, and in the oceans.

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Answer:

the process involves plates being dragged into the mantle at certain points and moving away from each other at others, in what has been dubbed 'the conveyor belt'.

Plate tectonics depends on the inverse relationship between density of rocks and temperature.

At mid-oceanic ridges, rocks are hot and their density is low, making them buoyant or more able to float. As they move away from those ridges they cool down and their density increases until, where they become denser than the underlying hot mantle, they sink and are 'dragged' under.

But three to four billion years ago, Earth's interior was hotter, volcanic activity was more prominent and tectonic plates did not become cold and dense enough to spontaneously sank.

The movement of the seafloor away from spreading ridges caused by topographic variations (the ridge is a topographic high) and density changes in the crust (density increases as newly-formed crust cools and moves away from the ridge).

To learn more about :  Seafloor

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