i need help and it’s for science cause i have a bad grade in it and have 3 days to get all my grades up so help pls?

Answer:

the last one

Explanation:

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Because hydrogen forms compounds with oxidation numbers of both +1 and -1, many periodic tables include this element in both Group IA (with Li, Na, K, Rb, Cs, and Fr) and Group VIIA (with F, Cl, Br, I, and At).

There are many reasons for including hydrogen among the elements in Group IA. It forms compounds (such as HCl and HNO3) that are analogs of alkali metal compounds (such as NaCl and KNO3). Under conditions of very high pressure, it has the properties of a metal. (It has been argued, for example, that any hydrogen present at the center of the planet Jupiter is likely to be a metallic solid.) Finally, hydrogen combines with a handful of metals, such as scandium, titanium, chromium, nickel, or palladium, to form materials that behave as if they were alloys of two metals.

There are equally valid arguments for placing hydrogen in Group VIIA. It forms compounds (such as NaH and CaH2) that are analogs of halogen compounds (such as NaF and CaCl2). It also combines with other nonmetals to form covalent compounds (such as H2O, CH4, and NH3), the way a nonmetal should. Finally, the element is a gas at room temperature and atmospheric pressure, like other nonmetals (such as O2 and N2).

It is difficult to decide where hydrogen belongs in the periodic table because of the physical properties of the element. The first ionization energy of hydrogen (1312 kJ/mol), for example, is roughly halfway between the elements with the largest (2372 kJ/mol) and smallest (376 kJ/mol) ionization energies. Hydrogen also has an electronegativity (EN = 2.20) halfway between the extremes of the most electronegative (EN = 3.98) and least electronegative (EN = 0.7) elements. On the basis of electronegativity, it is tempting to classify hydrogen as a semimeta

Explanation:

The periodic table is an arrangement of the chemical elements, organized on the basis of their atomic numbers, electron configurations and recurring chemical properties.

Answer:

The charge of an atom is the number of protons minus the number of electrons.

Answer:

the answer 32/43

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other, the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

a ⇒ b

c ⇒ x

So,  

The direct rule of three is the rule applied in this case as follows: If the change in water level is 0.05 inches per hour, what is the change in water level after 24 hours?

change in water level=1.2 inches

To pass a decimal number to a fraction, you must:

Put the decimal number in a fraction above a 1. That is, the decimal number is the numerator, 1 the denominator.

Find an equivalent fraction. That fraction will carry in the denominator a 1, an

Finally, the change in the water level of the pond after 24 hours is 1.2 inches or what is the same  inches

Option C - Electrons are outside the nucleus and and have a negative charge is the correct alternative.

We have electrons.

We have to determine their role inside the atom.

An electron is one of the subatomic particles within an atom. It is negatively charged particle whose magnitude is 1.6 x 10⁻¹⁹ C.

According to the question -

The role of electrons inside the atom is as follows -

Hence, Option C is the correct alternative.

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Answer:

2.41×10²³ molecules of water

Explanation:

Given data:

Mass of methane = 3 g

Molecules of water formed = ?

Solution:

Chemical equation:

CH₄ + 2O₂    →     CO₂  + 2H₂O

Number of moles of methane:

Number of moles = mass/ molar mass

Number of moles = 3 g/ 16 g/mol

Number of moles = 0.2 mol

Now we will compare the moles of water with methane.

               CH₄           :              2H₂O

                  1              :                  2

                0.2            :             2 × 0.2 = 0.4 mol

Molecules of water:

1 mole = 6.022×10²³ molecules of water

0.4 mol ×6.022×10²³ molecules of water / 1mol

2.41×10²³ molecules of water

Answer: Buy ram 3500 Laramie Longhorn

Explanation:

Answer:

12

Explanation:

Answer:

4 ATOME nitrogen in the formula

There are  20 nitrogen atoms in the chemical formula mentioned.

Chemical  formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols  of elements. It also makes use of brackets and subscripts.

Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form  is called empirical formula.

It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.They are used to describe the chemical reactions.

There are four types of chemical formula:

1)empirical formula

2) structural formula

3)condensed formula

4)molecular formula

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Answer: Acceleration is when something accels.

Or, in simple terms, when the velocity changes rapidly to a very quick speed.

Hope this answer helps you!

Best of Regards!

Answer:

oxygen is an element because it is a pure substance which cannot be split into simpler substances by chemical means

Answer:

A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding

Answer:

Explanation:

Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth. ... Gravity creates stars and planets by pulling together the material from which they are made. Gravity not only pulls on mass but also on light.

Answer: 42

Explanation: I took a quiz and had the same question.

Answer:

Answer:

Hi!

The best way you can receive a Brainliest is to help others. You shouldn't focus on receiving a brainliest, rather being glad you helped someone who needed it.

I hope you take this advice and answer a question! :)

Answer:

Helium

Explanation:

Answer:

A or Hydrotropism

Explanation:

Answer:

hydrotropism Explanation:

because hydro= water and topism= the turning part of an organism hope this helps!! <3

Answer:

Fireworks is exothermic

Endothermic is Cookies

Explanation:

Exothermic reactions transfer energy to the surroundings and the temperature of the surroundings increases. Endothermic reactions take in energy and the temperature of the surroundings decreases.

Hope this helps

If you could magically make two neutrons in the nucleus of an atom disappear, the atomic number and the electrical charge of that atom would remain unchanged. Neutrons do not carry an electrical charge so adding or removing them from the nucleus does not change the electrical charge of the nucleus. It does, however, change the mass of the nucleus. Adding or removing neutrons from the nucleus are how isotopes are created.

Protons carry a positive electrical charge and they alone determine the charge of the nucleus. Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number. So, adding or removing protons from the nucleus changes what element that atom is! For example, adding a proton to the nucleus of an atom of hydrogen creates an atom of helium. (Actually, a few neutrons have to be added as well to make the new nucleus stable, but the end result is still helium.) Keep in mind that atoms, by definition, are electrically neutral and always contain the same number of protons and electrons.

Answer:

cm is a measure of length not volume

Answer:

I think it's Cm:)

Hope this helps

Answer:

Prokaryotes (which are bacteria and archea)

Eukaryotes (which is plants, animals, protists and fungii)

Answer:

No, it looks like there is no gas forming no foaming or burning so it is not

Explanation:

O₂(g) as a reactant

In chemical reactions, there is a reaction between reagents and products

Reaction:

aA + bB ⇒ cC

Substances A and B are called a reactants

Substance C is called a product

In the above reaction:

CO functions as a product in the first reaction and functions as a reactant in the second reaction  

In the final chemical equation :

CO(g)+30₂(g) → CO₂(g)

O₂ is on the left so it is called the reactant

Answer: B. O₂(g) as a reactant

Answer:

I think its a and c

Explanation:

im smrt

Answer:

I think it's D

sorry if I'm wrong.

Explanation:

Options that are not characteristics of compound in the question is D. different samples have different properties.

Some of the properties of a compound are;

Therefore, option D is correct because a compound will only has its own properties not that

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Answer:

In a 7-step scientific method, Spongebob utilized the 6th step when He wrote a brief summary of the investigation, and Spongebob utilized the 7th step when He also determined that his hypothesis statement was not right and explained why it wasn't right by providing evidence from the investigation.

Explanation:

Scientific Methods are organized ways employed by scientists to tackle problems by providing solutions to the problem or make hypotheses to which other scientists build on to provide solutions to the problem.

The steps of the scientific method are:

Step 1- Understand the Problem

Step 2-  Make research

Step 3- Hypothesis.

Step 4- Conduct an experiment to test the hypothesis

Step 5- Observations.

Step 6-Results/Conclusion.

Step 7- Communicate your research

When Spongebob wrote a brief summary of the investigation, which means he had already conducted an experiment and had already made necessary observations and data collection, so he was at step 6. At step 6, he had analyzed the data collected.

When Spongebob determined that his hypothesis statement was not right and explained why it wasn't right by providing evidence from the investigation, then he was at the final step of the scientific method. Step 7 tells whether the hypothesis is true or false.

Answer:

hey im spongebob

Explanation:

:D