EMERGENCY!!! Can someone tell me the answer plz plz I’ll give you brainlist and points plz This is my final test No wrong answers

Answer:

46 percent of trees have been cut down.

Scienctists helps plants, but humans do destroy a lot of plants.

Scientists - helps increase plant growth.

Woodchoppers - helps decrease plant growth.

Answer:

Sodium

because it burns with a yellow-orange flame.

Explanation:

It relates with Barium which burns with yellowish green flame

Answer:

about 16

Explanation:

its 20 - ( approximately 5)

= approximately 16

Answer:

It should be (C) about 12cm

Answer:

I think crystallization is a write answer for this question

Explanation:

but according to this (E is the write answer)

Answer: 10 grams

Explanation: Original sample is 80 gram and every three days half of its composition decays so 80 down to 40 in the first 3 days, 20 in the next three days, and  10 in the last three days

Answer:

protons: 36

neutrons: 48

electrons: 36

Answer:

the noble gases

Answer:

[tex]\boxed {\boxed {\sf C. \ 30 \ m/s \ east}}[/tex]

Explanation:

Velocity is the vector measurement of the change in position over time. A vector measurement means the answer must include a magnitude (numerical value) and a direction.

Here are some units of velocity:

There are many other units, but m/s is the most common.

We can eliminate choice B and D, because the units (meters-m and meters per second squared-m/s²) are not for velocity.

We are left with choice A (30 m/s) and C (30 m/s east). Remember, velocity needs a number and a direction. C contains the direction east, so it must be the correct answer.  

Answer:

where an organism lives which includes everything that surrounds and influences the organism.

Noble gas located in the region D

Noble gas are located in group 18 in the periodic table consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), have a stable electron configuration where the valence electrons are 8(full outer shell of electrons), so it is very hard to react because of its stability

If we look at the periodic system of the elements, the noble gases are on the far right, so that in Figure 8 it is located in area D

And the other region :

A : alkali elements(group 1),

B : alkaline earth elements(group 2)

C : halogen elements(group 17)

Answer:

Osmosis

Explanation:

Water is very essential for the body. When we drink water, our blood cells absorbs water from the body. This happen by a process called as osmosis process. Osmosis is type of diffusion process.

Water along with oxygen and carbon dioxide are some of the simple molecules that moves into the blood cell. Osmosis is the process by which water molecules passes into the cell bodies through its semi permeable membrane.    

Answer:

A

Explanation:

A salad with lettuce, cheese, seeds, tomatoes, broccoli, and other vegetables is an example of a heterogeneous mixture.

Milk is not mixed with anything so that is incorrect

River water is mixed in with dirt and minerals so this one is incorrect

Beach sand is incorrect because you can see colored particles.

Answer:

option 1. Two substances in a mixture differ in density and particle size. These properties can be used to separate the substances. These properties can be manipulated in order to have a better separation between the two substances.

Explanation:

Answer:

Two substances in a mixture differ in density and particle size. These properties can be used to separate both of them using the separating funnel or using filtration (filter paper).

Explanation:

Since their densities are different, one substance should float above the other in the mixture which allows for the separating funnel to let the substance sinking below (with the heavier density) to flow out first before changing the beaker to let the lighter substance flow out.

The substance with a bigger particle size would not be able to pass through the filter paper unlike the substance with the smaller particle size as the filter paper's pores is not big enough for it to pass through, separating both substances (with one on the paper and the other outside the filter paper, preferably in the beaker placed below the paper).

Answer:

if you add a neutron to lithium-7 it becomes a compound nucleus of lithium-8

Answer:

The light microscope bends a beam of light at the specimen using a series of lenses to provide a clear image of the specimen to the observer.

Answer:

The value of the equilibrium constant (K) remains the same.

Explanation:

A state of dynamic equilibrium is said to have been achieved in a reaction system when the rate of forward reaction equals the rate of reverse reaction.

At equilibrium, doubling the initial concentration of reactants have no effect on the equilibrium constant K. The equilibrium will rather shift to the left or right as required in order to annul the constraint.

Answer:

C

Explanation:

Answer:

The Middle Years

Explanation:

Depending on the size of the star, the period of which thermal energy is created through the process of nuclear fusion can vary. However, for the life cycle of an average star, this can be roughly a few billion to 10 or even 15 billion years

Answer:

❤C. A liquad becomes a solid❤

Explanation:

✌When you freeze water its a scientific fact that it becomes solid.✌

Volume of Ammonia(NH₃) = 22.4 L

Given

Reaction

3CuO+2NH₃⇒ 3Cu + 3H₂O+ N₂

In the problem, the CuO coefficient should be 3 not 2

M CuO = 80

mass CuO = 120 g

Required

The volume of NH₃

Solution

mol CuO :

[tex]\tt mol=\dfrac{mass}{M}\\\\mol=\frac{120}{80}\\\\mol=1.5[/tex]

From the equation, mol ratio CuO : NH₃ = 3 : 2, so mol NH₃=

[tex]\tt \dfrac{2}{3}\times 1.5=1~mol[/tex]

Assume at STP(0 °C, 1 atm) ⇒1 mol = 22.4 L, then volume of NH₃=22.4 L

Answer:

Up to now, we have presented chemical reactions as a topic, but we have not ... A single-replacement reaction is a chemical reaction in which one element is ... single-replacement reactions will occur between two given reactants. This is ... Use the activity series to predict the products, if any, of each equation.

Explanation:

Answer:

2.75 × 10^-45 m

Explanation:

From;

E= hc/wavelength

h= Plank's constant= 6.6 × 10^-34 Js

c= speed of light=3× 10^8 ms-1

Wavelength = 6.6 × 10^-34 × 3× 10^8/7.21 × 10^19

Wavelength= 2.75 × 10^-45 m

Answer:

1.8069*10²⁴molecules of CO₂ and H₂O are produced.

Explanation:

C₃H₅OH + O₂ → CO₂ + H₂O

The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.

Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts

Left side: 3 C, 6 H and 3 O.

Right side: 1 C, 2 H and 3 O.

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.  

So, balancing the C:

C₃H₅OH + O₂ → 3 CO₂ + H₂O

Then:

Left side: 3 C, 6 H and 3 O.

Right side: 3 C, 2 H and 7 O.

Now, balancing the H:

C₃H₅OH + O₂ → 3 CO₂ + 3 H₂O

Then:

Left side: 3 C, 6 H and 3 O.

Right side: 3 C, 6 H and 9 O.

Finally, balancing the O:

C₃H₅OH + 4 O₂ → 3 CO₂ + 3 H₂O

Then:

Left side: 3 C, 6 H and 9 O.

Right side: 3 C, 6 H and 9 O.

Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then 3 moles of CO₂ and 3 moles of H₂O are produced.

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole and it applies to any substance.

Then the following rule of three applies: if 1 mole contains 6.023*10²³ molecules, then 3 moles of CO₂ or 3 moles of H₂O, how many molecules does it contain?

[tex]amount of molecules=\frac{3 moles* 6.023*10^{23} molecules}{1 mole}[/tex]

amount of molecules= 1.8069*10²⁴

1.8069*10²⁴ molecules of CO₂ and H₂O are produced.

Answer:

what r the options??????

Answer:

Explanation:

Firstly, let's define what ground and excited state electronic configuration.

Ground state electronic configuration is when the electrons of the atom are in there lowest possible energy level while excited state electronic configuration is when electron(s) have moved to a higher energy level. Examples of these are provided in the options

a. 1s²2s²2p⁴ - This is a ground state electronic configuration (of oxygen) because the electrons are in there lowest possible energy level.

b. This option is not displaying (it is displaying something like an image that isn't loading)

c. 1s²2s²2p³3s¹ - We can see from this that an electron jumped from 2p energy level to 3s (p energy level ought to be completely filled with 6 electrons before another electron moves to the next energy level) meaning the electron is in it's excited state thus this is an excited state electronic configuration (of oxygen).

d. 1s²2s¹2p² - We can see from this also that an electron jumped from the 2s energy level to the 2p energy level (making it 2p² instead of 2p¹ in the ground state). The 2s energy level should ordinarily have 2 electrons. Thus, this is an excited state electronic configuration (of boron).

e. 1s²2s²sp¹ - This is a ground state electronic configuration (of boron) since all the electrons are in there lowest possible energy level.

f. 1s²2s³ - This configuration is impossible because the s energy level should only contain a maximum of 2 electrons, thus impossible to have 3 electrons in the s energy level

Answer:

This molecule is AgN3

Explanation:

Answer:

AgN3

Explanation:

Mass of nitrogen N is given as 24.36 g

Molar mass of nitrogen N= 14 g/mol.

amount of substance in mol of N = mass/molar mass

=24.36 g/ 14 g/mol.

=1.74 mol.

Given mass of silver= 62,64 g.

Molar mass of silver Ag=107.87 g/mol

Number of mols=62.64 g ÷ 107.87 g/mol.

=0.58 mol.

Ratio of number of mol of N and number of mols of Ag = 1.74 mol / 0.58 mol

=3:1

Hence, empirical formula is AgN₃.

Answer:

Explanation:

the vector sum of all such forces which equals zero for an object at rest. CASE 1: Considering a basketball of weight 1kg, if it has been kept stationary on the ground, there are two forces acting on it. These are it's weight (gravity) and equal and opposite force from the ground (normal reaction).

Answer:

The net force is zero. :)

Explanation:

Answer:

D?

Explanation:

I think D hmm is the answer if I am wrong pls anyone or someone type the right answer but for me is d

Answer:

NOT D!!!!

Explanation:

I am taking the quiz on ck12, it is NOT "none of the above"