Which of the following statements about elements and atoms is true?

Answers

Answer 1

Answer:

the first one

Explanation:


Related Questions

please help I need to ace this test
When two atoms attach to each other by sharing electrons it is called a...

A: Covalent bond

B: Ionic bond

C: none of these - atoms can't bond to each other.

D: Nuclear bond

2nd question
Two hydrogen atoms bonded together form a compound
A: True
B: False

3rd question
Water is two hydrogen atoms bonded to an oxygen atom. This is an example of a compound

A: True

B: False
like I said I need help on this and I don't wanna fail

Answers

#1: A covalent bond

#2 False

#3True

Help me with homework.

Answers

The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same

Further explanation

Equation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)

H₂+O₂---> H₂O

Reactants : H₂, O₂

Products : H₂O

not balanced

H₂O₂ ---> H₂O+O₂

Reactants : H₂O₂

Products : H₂O, O₂

not balanced

Na+O₂ ---> Na₂O

Reactants : Na, O₂

Products :  Na₂O

not balanced

N₂+H₂ ---> NH₃

Reactants : N₂, H₂

Products :  NH₃

not balanced

P₄+O₂---> P₄O₁₀

Reactants : P₄, O₂

Products :  P₄O₁₀

not balanced

Fe+H₂O ----> Fe₃O₄ + H₂

Reactants : Fe, H₂O

Products :  Fe₃O₄

not balanced

How is the process of photosynthesis essential to sustaining life on Earth?​

Answers

Answer:

Explanation:

Photosynthesis is important to living organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. ... The importance of photosynthesis in our life is the oxygen it produces

Which of the following is an indication of a physical change?
O A. The formation of a new substance
O B. Giving off a smell
O C. A change in the shape of a substance
O D. The production of gas and heat

Answers

I would like to say c

Answer:

A change in the shape of a substance

Explanation:

Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

Use your answers from questions 1–3 as the basis for the first section of your lab report. This section provides your reader with background information about why you conducted this experiment and how it was completed. Outline the steps of the procedure in full sentences. It also provides potential answers (your hypothesis/es) relative to what you expected the experiment to demonstrate. This section should be 1–3 paragraphs in length.

Answers

Answer:

1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…."                        2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.

Explanation:

Answer: the correct answer is A

Explanation:

What happens to light waves as they enter the Earth's atmosphere?

Answers

Light waves slow down as they enter the Earth's atmosphere from space. Light waves slow down as they enter and then speed back up once they reach Earth.

The rate of a chemical reaction would be decreased by

Answers

Answer:

The tempreature???

Explanation:

Colder tempreatures lead to a slower chemical reaction and warmer tempreatures lead to a faster  chemical reaction.

if the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?​

Answers

Answer: 7 neutrons

Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:

14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)

What charges would an atom of Cesium and Radium form based on the octet rule

Answers

Answer:

1+

Explanation:

Hope this helped!

2. How can glass be a liquid if it's so hard?

Answers

Explanation:

Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.

Answer:

It's a liquid state before its cooled.

The specific heat of a certain type of metal is 0.128 J/(g⋅∘C). What was the intial temperature if 0.305 kJ of heat is added to 94.8 g of metal to reach a temperature of 85.0 ∘C?

Answers

The intial temperature : 59.865 °C

Further explanation

Heat added :

Q = m . c . ΔT

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

[tex]\tt 305=94.8\times 0.128\times (85-t_1)\\\\85-t_1=25.135\\\\t_1=59.865^oC[/tex]

Which of these ions has the correct charge?



O2-


B2+


P2-


Li2+

Answers

Answer:

02- i think your welcome hope it helps

2. Al(OH),(s) + 3 HCl(aq) à 3 H2O(l) + AlCl3(aq). This reaction shows how aluminum hydroxide
in antacid tablets neutralizes hydrochloric acid in the stomach. A tablet containing 0.25 g of
aluminum hydroxide is ingested by a patient with 0.88 g of hydrochloric acid in their stomach. Is
this tablet sufficient to neutralize the acid in the patient's stomach? Explain using stoichiometric
calculations. [4 marks]
I

Answers

This tablet insufficient to neutralize the acid in the patient's stomach

Further explanation

Reaction

Al(OH)₃(s) + 3HCl(aq) ⇒ 3 H₂O(l) + AlCl₃(aq)

0.25 g of  Aluminum hydroxide-Al(OH)₃ , mol (MW=78 g/mol) :

[tex]\tt \dfrac{0.25}{78}=0.00321[/tex]

mol HCl : mol Al(OH)₃ = 3 : 1

[tex]\tt mol~HCl=3\times 0.00321=0.00963[/tex]

mass HCl (MW=36,46 g/mol) :

[tex]\tt 0.00963\times 36.46=0.351[/tex]

0.351 < 0.88⇒this tablet insufficient to neutralize the acid

Which of the following most likely happens when thermal energy is removed from a chemical reaction?

Answers

Answer:

fewer collisions occur between particles or lowering the temperature

Explanation:


What is the total number of grams of a 32-gram sample of 32P remaining after 71.5 days of decay?

Answers

Answer:

1 g

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Half-life of phosphorus (t½) = 14.3 days

Amount remaining (N) =?

Next, we shall determine the rate of disintegration. This can be obtained as follow:

Half-life of phosphorus (t½) = 14.3 days

Decay constant (K) =?

K = 0.693 / t½

K = 0.693 / 14.3

K = 0.0485 /day

Finally, we shall determine the amount remaining as illustrated below:

Original amount (N₀) = 32 g

Time (t) = 71.5 days

Decay constant (K) = 0.0485 /day

Amount remaining (N) =?

Log (N₀/N) = Kt/2.303

Log (32/N) = 0.0485 × 71.5 / 2.303

Log (32/N) = 3.46775 / 2.303

Log (32/N) = 1.5058

Take the antilog of 1.5058

32/N = antilog (1.5058)

32/N = 32.05

Cross multiply

32 = N × 32.05

Divide both side by 32.05

N = 32 / 32.05

N = 0.998 ≈ 1 g

Thus, the amount remaining after 71.5 days is approximately 1 g.

The half-life of a radioactive substance refers to the time taken for the substance to Decay to half of its initial size. Hence, the mass of the substance left after 71.5 days is 1 gram.

Initial mass = 32 g Half life = 14.3 days

After 14.3 days ;

32 / 2 = 16 grams

After 14.3 × 2 = 28.6 days :

16/2 = 8 grams

After 14.3 × 3 days = 42.9 days :

8 / 2 = 4 grams

After 14.3 × 4 days = 57.2 days :

4 /2 = 2 grams

After 14.3 × 5 days = 71.5 days :

2 /2 = 1 gram.

Hence, the mass of the sample left after 71.5 days would be 1 gram.

Learn more : https://brainly.com/question/18766174

What product(s) are formed during this chemical reaction? (Will be two answers)

B(NO3)3 + KBr rightwards arrow


K(Br)3


KNO3


Br3(NO3)2


K3NO4


B(NO3)K


B3K3


BBr3


BK

Answers

Answer:

BK. BK. BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK BK

Identify a metal from the following
(1) Sulphur
(2) Boron
(3) Silicon
(4) Sodium

Answers

Answer:

sodium

Explanation:

it is an alkali metal

When 0.25 moles of NH3 are produced according to the reaction below, how many moles of H2 must have reacted?
N2 + 3 H2 --> 2 NH3
O 1.5 moles H2
O 0.38 moles H2
O 0.25 moles H2
O 0.17 moles H2

Answers

Answer:

Explanation:

by stoichiometry

nNH3/2=nH2/3

0.25/2=nH2/3

nH2=0.25×3/2

nH2=0.375 mol

so its 0.38 mol

Answer:

I have this quiz rn I will try 0.38 if it is right I’ll edit this and say that

Explanation:

You are doing math homework and get frustrated and throw the 7 kg book with a force of 47
Newtons. How much acceleration will the book have when you throw it?

Answers

Answer:

The answer is 6.71 m/s²

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

f is the force

m is the mass

From the question we have

[tex]a = \frac{47}{7} \\ = 6.714285...[/tex]

We have the final answer as

6.71 m/s²

Hope this helps you

A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is
(1) 1 (3) 12
(2) 11 (4) 23

Answers

Answer:

1

Explanation:

Which best explains why aluminum is a nonrenewable resource?

A)It cannot be quickly replaced.
B)It is expensive to process.
C)It conducts electricity.
D)It is useful to humans.

Answers

Answer:

A.) It cannot be quickly replaced.

Explanation:

Aluminum is extremely useful to humans but is semi-difficult to produce. Because of this, your answer will be numero uno. (Or A.)

someone help me please i’ll give brainly

Answers

Answer:

b

Explanation:

i looked it up on Google

What’s the answer????

Answers

Answer:

Greater

Greater

Explanation:

The amplitude of a wave is the height of the wave or the vertical displacement of the wave motion. We determine a wave amplitude usually by looking at the graph of the wave.

Amplitude is directly proportional to the energy of a wave. The higher the amplitude of a wave, the more its energy.

Frequency is the number of waves that passes a point at a particular instance of time. It is also directly proportional to the energy carried by a wave. The higher the frequency of a wave, the greater its energy.

if a star were 36 trillion miles from the earth it would be about ___ light years from the earth​

Answers

Answer:

6.12light years

Explanation:

Given parameters:

Distance of star from earth  = 36 trillion miles

Unknown:

Distance in light years  = ?

Solution:

A light year is the distance light travels in one year.

  1 mile  = 1.7 x 10⁻¹³ light years

 36 trillion miles  = 36 x 10¹² x 1.7 x 10⁻¹³ light years

                             = 6.12light years

We can change the substance chemically by
freezing it.
True or false​

Answers

The answer for the forgiving question above hypothetically speaking they a screen with imagination is going to be true
It’s mostly going to be true

I need some help with this

Answers

newton’s first law of motion is also known as the law of inertia

(02.05 LC)
Which type of heat transfer takes place when objects touch each other? (3 points)
A Conduction

B Convection

C Radiation

D Temperature

Answers

Answer: That is Conduction

Explanation:

:)

Conduction

reason: Conduction is the transfer of heat through contact between items.

(Brainliest, please?)

There are several different models that represent compounds. One type of model is shown.

3 C's connected in a line by 2 black lines. The first and third C's each have 3 H's connected to them by a single black line each. The middle C has 2 H's connected to it by a single black line each.
What type of model is shown?

Answers

A) structural formula

On edge

Answer:

A

Explanation:

how to know the unknown metal in flame test

Answers

Explanation:

The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light

Which screw would create a strong hold?

A: The screw with 9 wraps.
B: The screw with 2 wraps.
C: The screw with 10 wraps.
D: The screw with 6 wraps.

Answers

Answer:

The screw with 10 wraps is the correct answer

Explanation:

The screw with 6 wraps would create a strong hold.

What do you mean by screw?

The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.

In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.

Thus, The screw with 6 wraps would create a strong hold.

To learn more about Screw, refer to the below link:

https://brainly.com/question/24168324

# SPJ5

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