3. What is SI system? Why has SI system been developed? Give reasons​

Answer:

Detail is given below

Explanation:

Atomic radii trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also  decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.

In A we can see that there is one positive charge and force of attraction is 2.30×10⁻⁸ N and distance is 0.10 nm

In B we can see that negative charge is further away from nucleus because of greater distance thus force of attraction will be less. 0.58×10⁻⁸ N

In C this distance further increases and force also goes in decreasing 0.26×10⁻⁸ N.

Answer:

The answer is D and B

Explanation:

It is a quanity because it is because it is being measured in terms of numerical information.

Its is also continuous beause it does not show random change in the mathmatics, it it a slow yet constant change of measurement.

Answer:

The two substances are Grease and Oil.

Explanation:

- Grease is used for other lubrication outside of the engine when it is really cold.

- Oil is used for lubricating when your engine is really hot.

Answer:

No.

Explanation:

According to the formula б/X=б/√n, as more measurements are made, the uncertainty gets smaller.

Answer: hope this helps!

Explanation:

Answer:

false

Explanation: An organ is a structure that is composed of at least two or more tissue types and performs a specific set of functions for the body.

plz mark brainliest

Answer:

51.04% of protein in the sample

Explanation:

The question is the percentage of protein in the sample and the acid is 0.2496 M  H2SO4.

First we need to calculate the moles of sulfuric acid that react:

Moles of sulfuric acid added:

0.0500L * 0.2496mol/L = 0.01248 moles of sulfuric acid.

Moles in excess:

0.01990L * 0.5510mol/L = 0.01096 moles NaOH * (1 mol H2SO4 / 2 moles NaOH) = 0.00548 moles of sulfuric acid.

Moles that react:

0.01248 moles - 0.00548 moles = 7.0x10⁻³ moles of H2SO4 react.

Based on the reaction, the moles of NH3 = Moles of N are:

7.0x10⁻³ moles of H2SO4 * (2moles NH3 / 1 mole H2SO4) = 0.014 moles NH3 = Moles N

The mass of nitrogen (Molar mass: 14g/mol):

0.014 moles N * 14g/mol = 0.196g of N.

The percentage of N is:

0.196g N / 2.400g = 8.17% of N

6.25 times the percentage of nitrogen is the percentage of protein:

8.17%*6.25 =

Answer:

Aluminum isn't found pure naturally, but its found mixed with other minerals in the earth. It's used to make cans, foil, kitchen utensils, window frames and even deodorant

Explanation:

Answer:

Twelve electrons

Explanation:

If we look at the product side, we will notice that iron lost twelve electrons and oxygen gained twelve electrons.

Hence, we have 4Fe^3+ and 2O3^2- showing twelve electrons lost/gained.

Answer:

How many electrons does the iron half-reaction lose?

12

How many electrons does the oxygen half-reaction gain?

12

What is the total number of electrons that are moved in this oxidation-reduction reaction?  12

Explanation:

Answer:

Five molecules of nitrogen and eight molecules of sulfur

Explanation:

Answer:

Increase the pressure of the gas

Explanation:

According to the Pressure law, for a fixed mass of gas, at a constant volume (V), the pressure (P) is directly proportional to the absolute temperature (T).

From the kinetic molecular theory, gases are composed of particles which are in constant motion, colliding with themselves as well as with the walls of their container.

When the temperature of these gas molecules is increased, the molecules acquire more kinetic energy and the rate of collisions increases. Since the container cannot expand, the increase in pressure is due to the increase in collisions between the molecules of the gas as well as with the walls of their container.

Answer:

False

Explanation:

Its F

Answer:

1.51*10^23 atoms Rb

Explanation:

Use dimensional analysis

Answer:

Explanation:

set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules[1

Answer:

Questions 1 is Letters

Questions 2 is H I believe

Questions 3 is hardness

Explanation:

hope I helped

Answer:

1. c

2. a

3. b

you're welcome

Answer:

I'm pretty sure it is the patriarch

Explanation

Patriarch means the head of a family or tribe.

Answer:

D

Explanation:

Answer:

I think its intermolecular

Explanation:

I'm sorry if it is wrong

Answer:

intermolecular forces

Explanation:

Answer:

It all started with the big bang.

The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching).

Answer:

Electron Configurations - Solutions

Note: The electron configurations in this worksheet assume that lanthanum (La)

is the first element in the 4f block and that actinium (Ac) is the first element in the

5f block. If your periodic table doesn’t agree with this, your answers for elements

near the f-orbitals may be slightly different.

1) sodium 1s2

2s2

2p6

3s1

2) iron 1s2

2s2

2p6

3s2

3p6

4s2

3d6

3) bromine 1s2

2s2

2p6

3s2

3p6

4s2

3d104p5

4) barium 1s2

2s2

2p6

3s2

3p6

4s2

3d104p6

5s2

4d105p6

6s2

5) neptunium 1s2

2s2

2p6

3s2

3p6

4s2

3d104p6

5s2

4d105p6

6s2

4f145d106p6

7s2

5f5

6) cobalt [Ar] 4s2

3d7

7) silver [Kr] 5s2

4d9

8) tellurium [Kr] 5s2

4d105p4

9) radium [Rn] 7s2

10) lawrencium [Rn] 7s2

5f146d1

11) 1s2

2s2

2p6

3s2

3p4

sulfur

12) 1s2

2s2

2p6

3s2

3p6

4s2

3d104p6

5s1

rubidium

13) [Kr] 5s2

4d105p3

antimony

14) [Xe] 6s2

4f145d6

osmium

15) [Rn] 7s2

5f11 einsteinium

16) 1s2

2s2

2p6

3s2

3p6

4s2

4d104p5 not valid (take a look at “4d”)

17) 1s2

2s2

2p6

3s3

3d5

not valid (3p comes after 3s)

18) [Ra] 7s2

5f8

not valid (radium isn’t a noble gas)

19) [Kr] 5s2

4d105p5 valid

20) [Xe] not valid (an element can’t be its own electron configuration)

Answer:

I just finished a unit on Scientific Method in my science class! Anyway, it's defined in the screenshots below. Hope this helps!

Answer:

osmosis. I

Explanation:

If an object/ cell is placed in a solution where the concentration is more or stronger than itself(hypertonic solution), it shrinks because water moves out of it, but if it is placed where the concentration of the surrounding solution is lesser than its concentration(hypotonic solution), it swells and can burst because water moves into it. So the mass of the egg will decrease because it is placed in an hypertonic solution (salt water) and the concentration of the salt water is stronger than its concentration

Answer:

D

Explanation:

Answer:

1. D

2. A

Explanation:

Answer:

Constant

Explanation:

Trust

Answer:

Attraction

(e-) ---> <--- (H+)

Repulsion:

<---(e-) (e-)-->

Neutral:

(e-)       (Helium)

Explanation:

Accordingly to coulomb's law:

In the attraction, the hydrogen without an electron has a positive charge and needs to be fulfilled with a negative charge found in an eletron.

In the repulsion, both electrons has the same charge and repulse each other.

In the neutral case, the Helium is highly stable therefore the electron is not attracted.

Answer:

grass

Explanation:

ice and tile are smooth and without any bumps or large ridges, unlike grass which is spiky and flexible. grass will most likely slow down a ball that is rolling, unlike answer choices B and C.

Answer:

grass

Explanation:

ice and tile are bothe a flat surface where grass has texture