Nguyên tố hoá học là gì

Answer:

Thanks!!!

Explanation:

Answer:

true

Explanation:

Answer:

the answer to this problem is a

Answer:

big ablsolty long pp

Explanation:

dong

Answer:

Facts: A D and maybe C I think you are intended to say C

Explanation:

A is certainly not an opinion. It is either true, or it is not. I think it is intended as a fact.

B is an opinion (which I think is true)

C is kind of iffy. It might be true and it might be an opinion. In looking it up, it is factually incorrect. Cats are related to wildcats in the middle east.

D is also iffy. They can just eat disease free rodents. I'd classify it as more opinion than fact.

E. definitely an opinion.

Answer:

The food coloring mixes through the hot water faster than it mixes with the cold water. The reason for this is because  in hot water, the water molecules have more energy and are moving faster than the molecules of cold water. This makes it way more easier for the dye to get mixed throughout the hot water.

Explanation:

Answer:

1)physical change

Explanation:

2)chemical change

Answer:

9.1093837015 × 10^−31 kg

Very small mass

Answer:  The combustion of methane (CH4) with O2.

Explanation:  This is a chemical reaction involving carbon:

 CH4 + 2O2 = CO2 + 2H2O

Answer:

C

Explanation:

alkali metals are the Group I elements, which have 1 electron in their valence shells

Answer:

Alkali metals are the elements which have only one valence electron in their outermost or ultimate shell.

Explanation:

Alkaline Earth metals have 2 valence electron in their outermost shell and readily give up their 2 electron to achieve stability.

Rare Earth Metals have 3 valence electron in their outermost shell and they have high magnetic moments and divert range of magnetic structure.

Alkali Earth metals have 1 valence electron.

Transition metals generally have 2 valence electron .

Learn more on:

https://brainly.com/question/3062525

Explanation:

Sublimation is the conversion of a substance from the solid to the gaseous state without its becoming liquid. ... Freeze-drying of food to preserve it involves sublimation of water from the food in a frozen state under high vacuum. See also vaporization; phase diagram.

Answer:

If the sugar concentration level of the must becomes too high at any given point--either at the beginning or during the fermentation--it starts to have an inhibiting effect on the yeast's ability to produce alcohol. In other words, the higher sugar concentration starts to act as a preservative effecting the fermentation in a negative way.

Explanation:

Fermentation is the process by which yeast converts the glucose in the wort to ethyl alcohol and carbon dioxide gas -- giving the beer both its alcohol content and its carbonation.

Explanation:

Answer:

solutions is a homogenous mixture while colloids and suspensions are heterogeneous mixtures made up of 3 or more substances

Explanation:

homogeneous- made up of one thing

heterogeneous- made up of 2 or more things

The parts of the text on the page that use examples of how the flow of matter through a system is energy driven and has the capacity to do work are;

1) The flow of water down rivers passing through hydro power dams to perform the following works;

2) The flow of electrons that corresponds to the flow of electricity (in the reverse direction) to perform the following works;

3) The lifting of the hammer by the cam which gains gravitational potential energy that is converted to kinetic energy as the hammer drops

The hammer is repeatedly lifted and dropped by the cam to do the following work

4) The chemical potential energy stored in bonds by virtue of the relative atomic distances which produces kinetic energy from the chemical potential energy

Lear more about energy conversion here:

https://brainly.com/question/15105485

Answer:

3 exothermic reaction. only that much

Hi,

These are the answers.

• Question 2. C , Substance dissolves

• Question 3. D , Exothermic reaction

• Question 4. C , Endothermic reaction takes place

• Question 5. A , the products formed has more energy than reactants

Hope it helps you... pls mark brainliest if it helped you

Answer:

increase with increases in temperature

Explanation:

please mark me brainleast

The correct answer to the question is Rubidium (Rb)

Rubidium (Rb) is a group 1 element and as such, it can form bond by losing it's valence electron (i.e 1 electron) easily.

Gallium (Ga) is a group 13 element. It can only form bond by losing it's 3 valence electrons.

Argon is a group 18 element. This group has completely filled outermost shell and are very stable. They do not involve in bond formation.

Iodine (I) is a group 17 element. It is more difficult for this group to lose its 7 valence electrons hence, they form bond by accepting 1 electron.

With the above information, we can conclude that Rubidium will most likely lose electron to form bond.

Learn more: https://brainly.com/question/13178080

Answer:

(Question 1)Which element would most likely lose electrons to form positive ions when bonding with other elements?

(Answer) rubidium (Rb)

(Question 2) Which statement about sodium chloride is correct?

(Answer) The sodium atom transfers electrons to the chlorine atoms to form ionic bonds.

(Question 3) Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?

(Answer) nitrogen (N) and oxygen (O)

(Question 4) Which phrase best describes electronegativity?

(Answer) the relative strength with which an element attracts electrons in a chemical bond

(Question 5) Based on the information in the table, which pair of elements would likely form the least polar bonds with each other?

(Answer) bromine and nitrogen

Explanation:

just finished the quick check enjoy UwU

Answer:

Freezing water and cracking limestone are physical changes.

Answer:

» Reactivity and color

Explanation:

though color is very minor answer because it also relates to a physical property.

[tex].[/tex]

Answer:  1.8x10^-4 M H+

Explanation:  The number of moles of NaOH added to the 100 ml soultion will be equal to the number of moles of H+ present in that solution.  

Moles NaOH in 7.2 ml of 2.5x10^-3 M NaOH

(2.5x10^-3 M NaOH) is the same as 2.5x10^-3 moles NaOH/liter

(2.5x10^-3 moles NaOH/liter)*(7.2 ml)*(1 liter/1000ml) = 1.8x10^-4 moles NaOH used to titrate 100 ml of the acid.  That means there was 1.8x10^-4 moles of H^+ in 100 ml.  

Concentration of H^+ = (1.8x10^-4 moles H)/0.100 l) = 1.8x10^-4 M H+

(pH of 3.74)

Answer:

ans:Ne=2,8,1

ans:2,8,7

Answer:

81 °C

Explanation:

This is a calorimetry question so a few things you will need for this. The calorimetry equation q=mcΔT & the specific heat of water (4.2J/g•°C). Other definitions are:

q = heat added/released by a sample

m = mass of sample

c=specific heat of sample

ΔT = change in temperature

from here we can rearrange the equation to state:

q/(mc) = ΔT

1200J/((20.0g)(4.2J/g•°C)) = ΔT

14°C = ΔT

If the starting temperature was 95.0°C and we know that the temperature was cooled by 14°C then the final temperature of the water would be 81.

Answer:

C. 81 c

Explanation:

took the test :)

Explanation:

No, that would be incorrect

Answer:

There arre two main parts of the atom, the nucleus and the orbital rings. The three subatomic particles are contained in each of these, the proton and neutron together in the nucleus and the electrons orbiting in the rings.

Answer:

A. The product formed have more energy than the reactants.

This is because it is an endothermic reaction.

[tex].[/tex]

Answer:

D=1.56g/mL

Explanation:

Density=m/v

D=14.06g/(24mL-15mL)

D=14.06g/9mL

D=1.56g/mL

Answer:

C and D

Explanation:

A reaction is said to be decomposed, if the reactant is broken down to liberate single element.

Answer:

I don't know

Explanation:

is today your test

Answer:

answer

Explanation:

Area : Square Meters,

Volume : Cubic Meters,

Density : Kilograms per Meter Cube,

Velocity : Meters per Second Squared,

Force : Newtons (Mass multiplied by Acceleration or Mass multiplied by Displacement divided by Time squared)…..

The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;

The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and  ZnCl2(aq) in the remaining solution.

Hence;

Mass of ZnCl2(aq) formed = 36.309g - 35.123g  = 1.186g

Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]

[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles

From the reaction equation;

[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]

To obtain the amount of Zn reacted

1 mole of Zn yields 1 mole of ZnCl2

x moles of Zn yields 0.0087 moles of ZnCl2

x = 0.0087 moles of Zn

a) 1 mole of Zn yields 1 mole of H2

0.0087 moles of Zn yields 0.0087 moles of H2

Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams

b)

Mass of Zn reacted =  0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams

c)

Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %

https://brainly.com/question/14595258