can you guys help me please? I dont get what im supposed to do here.

Answer:

the answer is 2 valence electrons

Answer:

O E = hf

Explanation:

Answer:

Energy is halved.

Explanation:

Energy and Frequency are directly proportional. If frequency decreases, energy increases. If frequency increases, energy increases. If frequency is halved, energy is also halved.

Answer:c

Explanation:

Answer:

C is the answer

are in the outermost energy level

Answer:

Lithium oxide.......................

Explanation:

6. magnicium chloride

2.Barium chloride

3. calcium nitride

4. lithium oxide

5. Aluminium sulphide

plzz mark me brainliest

Answer:

C

Explanation:

Answer:

D. Ruler

Explanation:

Use the formula to find the volume of a cuboid by measuring the length, width, and height and multiplying all of them by each other.

Answer: A

Explanation: Mortality means death. And it is a primary goal of Development Goals

Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.

Mortality is defined as the state of the individual being dead. The mortality rate is the death rate of a population which is calculated on the basis of the deaths in the particular region.

Mortality as one of the components of demography is measured as mortality rate.

Mortality meaning provides the basis for mortality rate and its estimation. Mortality is the possibility of and susceptibility to death, and hence, the rate of mortality or the death rate is the measurement of the number of deaths that occur in a particular population, scaled to the size of that population per unit of time.

Therefore, Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.

Learn more about Mortality, here:

https://brainly.com/question/6344227

#SPJ3

Answer:

A

Explanation:

Tetrahedral

The term that describes the molecular structure is Tetrahedral. The correct option is A.

The molecular structure is the structure of the molecular compounds. It tells the presence of ions and bonds in a compound. It is the arrangement of atoms, groups, or ions in a molecule, as well as the quantity and distribution of chemical bonds.

The use and importance of molecular structure are comprehending Nature's complex design principles and blueprints depend on understanding molecular structure.

Perhaps we can start to imitate her lovely items more cheaply and with less negative environmental effects if we can comprehend her plans and fundamental materials. The given compound is tetrahedral.

Thus, the correct option is A. Tetrahedral.

To learn more about molecular structure, refer to the link:

https://brainly.com/question/503958

#SPJ2

Incomplete question. However, I provided a specific example of stewardship of the atmosphere.

Explanation:

First, note that the term stewardship refers to the belief that humans are obligated to take care and look after our environment (which includes the atmosphere.

An example of this is: deciding to change our mode of transportation: What this entails is that we may decide to switch to riding a bicycle to places rather than going by car. By so doing you will be reducing the number of greenhouse gases emitted into the environment as bicycles do not emit harmful gases when used.

Answer:

Explanation:

Ammonia consist of nitrogen and hydrogen.

Chemical equation:

N₂ + H₂    →   NH₃

Balance chemical  equation:

N₂ + 3H₂    →   2NH₃

We can see that nitrogen and hydrogen react with each other and from ammonia.

Nitrogen is present in group 5A.  The atomic number of nitrogen is 7.  Its atomic mass is 14 amu.  It has 5 valence electron.

Electronic configuration:

N₇ = 1s² 2s² 2p³

we can see there are five electron in outer most shell. Thus, nitrogen needs three more electrons to complete the octet.  When it combine with other atoms it gain three electron from them

While hydrogen is present in group 1A. It has one valence electron. In ammonia (NH₃) when nitrogen react with hydrogen it gain three electrons thus three atoms of hydrogen combine with one atom of ammonia because one hydrogen atom can share only one electron. Covalent bond is formed between nitrogen and hydrogen and new substance formed is called ammonia.

Answer:differentiate between two compounds i think!

Explanation: taking a test!

Answer:(1) differentiate between two compounds

Explanation:

A Chemical property tells us the  characteristics of a particular matter or substance after a  chemical change. This property helps us to differentiate a compound from another or differentiate   elements or substances. Examples of a Chemical property are  acidity, reactivity and heat, etc .

For example to differentiate between Water H2O and  Hydrogen peroxide, H202

Even though they are made up of  oxygen and hydrogen. Hydrogen peroxide  (H2O2), has  more(1) oxygen than water (H2O).

Using Acidity as a chemical property to differentiate these substances

Water, H20  is amphoteric in nature ie having both acidic and basic properties, while H202 is a weak acid.

See related question here: https://brainly.com/question/19594290

Answer:

mole = no of atoms/ 6.02E23.... so therefore answer= 5.6E22/6.02E23= 0.093✨

Answer: A Meteor

Explanation:

A streak of light in the sky and says she is seeing a shooting star. She's most likely observing is a meteor. Therefore, option C is correct.

A meteor is an object from space or a meteoroid that touches down on Earth. The air on the space rock creates drag that causes it to become incredibly heated as it falls toward Earth.

When the earth travels through cometary debris during its orbit around the Sun, meteor showers will result. Although the Earth's orbit around the Sun is nearly round, the majority of comets have very elliptical orbits.

A meteoroid becomes a meteor, or a streak of light in the sky, if it gets close enough to Earth and enters its atmosphere. These light striations are sometimes referred to as "shooting stars" due to their appearance. However, stars are not what meteors are.

Thus, option C is correct.

To learn more about meteor, follow the link;

https://brainly.com/question/11504264

#SPJ2

Answer:

Veins carry oxygen poor blood back to the heart while arteries carry oxygen rich blood

Answer:

A. element

Explanation:

Answer: Element

Explanation: A substance that is composed of only one type of atom is called an element. At this point, what should amaze you is that all forms of matter in our universe are made with only 118 different building blocks.

Emission lines are seen as coloured lines on a black background. Absorption lines are seen as black lines on a coloured background. The presence of spectral lines is explained by quantum mechanics in terms of the energy levels of atoms, ions and molecules.

i hope it is helpful:) mark as brainlist

Answer:

Layer A is the youngest

Explanation:

It is at the top, it has all of the dinosaur bones which got buried after earth got hit with an asteroid and they went extinct. Layer D started it and all of these years dirt, soil, and fossils have been gathering making each layer before older and older.  

Answer:

The compounds in the samples will leach into the pool of developing solvent resulting in poor resolution.

Explanation:

The aim of thin layer chromatography is the separation of a mixture. Usually, the stationary phase is spotted with the mixture. A mark is made with a pencil at the point to be spotted.

It is necessary to note that the solvent must be below the spot where the mixture is. This is because, if the solvent is above the spot of the mixture to be separated, the components of the mixture will dissolve away in the solvent resolution in poor separation. This is exactly what will happen when the sample is spotted at 1.0 cm above the bottom when the solvent is 1.2 cm above the bottom.

Answer:

Tbh i rlly dont think that many will.  Most may succeed  in doing so. But i mean come on its 2020 anything can happen.

Explanation:

Answer:

yes 100% what reasons r there to not tho

Explanation:

Answer:

In a hydraulic lift system, the output force is greater than the input force because the pressure acting on the output piston is greater than the pressure acting on the input piston.

Explanation:

Answer:

Nuclear fission

Explanation:

This reaction is called a nuclear fission reaction. In this reaction, a radioactive decay process occurs in which a heavy nucleus spontaneously disintegrates into two lighter nuclei and several neutrons, with the release of a large amount of energy.

Answer:

hydrogen is a non-metal, and has one valence electron.

Explanation:

Hope this helps!!

Hydrogen shows properties of both metals and nonmetals. However, hydrogen is placed with the alkali metals since it contains one valence electrons.

Hydrogen is the first element in the periodic table. It has only one electron and it is the valence electron of hydrogen. Therefore, hydrogen is placed in the first group of periodic table.

Hydrogen needs one more electrons to become stable. The 17th group elements halogens also have a valency of  one. Hence, hydrogen shows some chemical similarities with halogens also.

Mostly hydrogen forms covalent bonds like non-metals and in rare cases, hydrogen forms ionic bonds by donating its electron. Therefore, hydrogen is mostly considered as a non-metal.

Find more on hydrogen;

https://brainly.com/question/11837837

#SPJ2

Notes, Pitches, Articulation, Phrasing, and Musical Extras.

Answer:

[tex]\frac{3}{2}[/tex]

Explanation:

No of moles : [tex]\frac{given mass}{atomic mass}[/tex]

so the given mass is 42 gm and atomic mass of silicon is 24 when u solve it u get 3/2

9. (80-32)5/9

48×5/9

240/9

26.66°C

9. (90-32)5/9

58×5/9

32.22°C

10 (212-32)5/9

180×5/9

20×5

100°C