Robert Hooke used a microscope to observe tiny spaces in
dead cork bark.
What did his observations lead to the discovery of?
A. Bacterial cells
B. Plant cells
C. Cell division
D. Cell organelles

Answers

Answer 1

Explanation:

B. Plant cells is the correct answer

Answer 2

Answer:

plant cells cause the plant cells was his first discorvery


Related Questions

1. Determine the number of significant figures in the following measurements.

a. 38.7 g 3 significant figures
b. 3 486 002 kg 7 significant figures
c. 0.00013 cm
d. 0.001400 g/L
e. 9 740 000 nm/s

Answers

Answer:

2 and 4 and 3

Explanation:

in c. leading 0's are never significat. Numbers 1-9 are always significant.

d. leading 0's are never significant. numbers 1-9 are always significant. ending 0's are only significant when there is a decimal.

e. numbers 1-9 are always significant. 0's are not significant because there is no decimal.

__________ occurs when a gas changes directly into a solid without going through a liquid phase. *
sublimation
vaporization
condensation
deposition

Answers

Answer:

Deposition

Explanation:

Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation.

Cations have positive charges. Anions have negative charges. What force draws the two together?

Answers

Answer:

electrostatic attraction

Explanation:

Electrostatic attraction refers to the electrostatic force of long-range interaction occurring between the attractive electrostatic adsorption in aqueous solution with differently charged particles or uncharged particles.

Answer: Electrostatic attraction.

Explanation:

D. liquid
18. Which one is the oxidizing agent in the following reaction?
CuO + H2 cu + H2O
A. Cuo
B. H2
C. Cu
D. H2O​

Answers

Answer: H2O

Explanation: The given balanced chemical reaction is,

This reaction is a reversible reaction.

The rate of forward reaction will be,

The rate of backward reaction will be,

And at equilibrium the rate of reaction is equal to the rate of backward reaction divided by the rate of forward reaction.

dose someone like to talk and will you help me to, if not we can talk

Answers

Answer:

wsppp

Explanation:

Answer:

hi.. (:

Explanation:

Blonde hair is a dominant trait. (True or flase)​

Answers

Answer:

False

Explanation:

Answer:

false

Explanation:

what is the molar mass of tin (II) sulfate?

Answers

Answer:

214.77 g/mol

Explanation:

Tin(II) sulfate

From Wikipedia, the free encyclopedia

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Tin(II) sulfate

Tin(II) sulfate crystallizes in an heavily distorted barium sulfrate structure.

Unit cell of tin(II) sulfate.

Names

Other names

Stannous sulfate

Identifiers

CAS Number  

7488-55-3 ☑

3D model (JSmol)  

Interactive image

ChemSpider  

21106484 ☑

ECHA InfoCard 100.028.457 Edit this at Wikidata

EC Number  

231-302-2

PubChem CID  

62643

UNII  

0MFE10J96E ☑

CompTox Dashboard (EPA)  

DTXSID20884389 Edit this at Wikidata

InChI[show]

SMILES[show]

Properties

Chemical formula SnSO4

Molar mass 214.773 g/mol

Appearance white-yellowish crystalline solid

deliquescent

Density 5.15 g/cm3

Melting point 378 °C (712 °F; 651 K)

Boiling point decomposes to SnO2 and SO2

Solubility in water 33 g/100 mL (25 °C)

Structure[1]

Crystal structure Primitive orthorhombic

Space group Pnma, No. 62

Lattice constant  

a = 8.80 Å, b = 5.32 Å, c = 7.12 Å[2]

Hazards

NFPA 704 (fire diamond)  

NFPA 704 four-colored diamond

010

Flash point Non-flammable

Lethal dose or concentration (LD, LC):

LD50 (median dose) 2207 mg/kg (oral, rat)

2152 mg/kg (oral, mouse)[3]

Related compounds

Other anions Tin(II) chloride, tin(II) bromide, tin(II) iodide

Other cations Lead(II) sulfate

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tin(II) sulfate (SnSO4) is a chemical compound. It is a white solid that can absorb enough moisture from the air to become fully dissolved, forming an aqueous solution; this property is known as deliquescence. It can be prepared by a displacement reaction between metallic tin and copper(II) sulfate:[4]

Sn (s) + CuSO4 (aq) → Cu (s) + SnSO4 (aq)

Tin(II) sulfate is a convenient source of tin(II) ions uncontaminated by tin(IV) species.

Answer:
214.77 g/mol

Atoms and elements are examples of

Answers

Answer:

A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing just one proton and one electron.

Which are examples of science rather than pseudoscience? Check all that apply.

Answers

Answer:

The second choice and the fourth choice are both based on science fact. The others are examples of pseudoscience.

the answers would be b. and c. because the others aren’t science

A balloon holding a 3.0 L volume of gas at sea level is suddenly
released by the child holding it. The balloon travels upwards until the
pressure around the balloon is 0.60 atm. Assuming isothermal
conditions, the new volume inside the balloon would be

Answers

Answer:

If you know your gas laws, you have to utilise a certain gas law called Charles' Law:

V

1

T

1

=

V

2

T

2

V

1

is the initial volume,

T

1

is initial temperature,

V

2

is final volume,

T

2

is final temperature.

Remember to convert Celsius values to Kelvin whenever you are dealing with gas problems. This can be done by adding 273 to whatever value in Celsius you have.

Normally in these types of problems (gas law problems), you are given all the variables but one to solve. In this case, the full setup would look like this:

2.75

291

=

V

2

318

By cross multiplying, we have...

291

V

2

= 874.5

Dividing both sides by 291 to isolate

V

2

, we get...

V

2

= 3.005...

In my school, we learnt that we use the Kelvin value in temperature to count significant figures, so in this case, the answer should have 3 sigfigs.

Therefore,

V

2

= 3.01 L

Explanation:

please mark me as the brainliest answer and please follow me

Answer:

6L im not completly sure but i wouldnt risk it

Explanation:

Which has a lower freezing point oxygen or ethanol

Answers

Answer:

Oxygen

Explanation:

i REALLY think it is

How many moles of KCl are contained in this solution?

0.486 L of a 2.0 M KCl solution

Answers

Answer:

0.972mol

Explanation:

Given parameters:

Volume of Solution of KCl = 0.486L

Molarity = 2.0M

Unknown:

Number of moles of KCl in solution = ?

Solution:

To find the number of moles of KCl in this solution, use the expression below;

  Number of moles  = molarity x volume

Insert the parameters and solve;

  Number of moles  = 0.486 x 2  = 0.972mol

Why does the s orbital fill before the p orbitals?
A. The s orbital is lower in energy than the p orbital.
B. The s orbital holds fewer electrons than a p orbital.
C. The s orbital belongs to a different energy level than the p orbital.
D. The s orbital is higher in energy than the p orbital.

Answers

Answer: A. The s orbital is lower in energy than the p orbital

Explanation: Just did test

The S-Orbital fill before the p-orbital Because, The s-orbital is lower in energy than the p-orbital. Hence, Option (A) is correct.

What is Afbau principle?

The aufbau principle, from the German Aufbauprinzip, also called the aufbau rule, states that in the ground state of an atom or ion, electrons fill subshells of the lowest available energy, then they fill subshells of higher energy.

For example, the S subshell is filled before the P subshell is occupied.

Therefore, The S-Orbital fill before the p-orbital Because, The s-orbital is lower in energy than the p-orbital. Hence, Option (A) is correct.

Learn more about Energy here ;

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What is the frame of reference?

Answers

Answer:

Frame of Reference

The fixed background surrounding an object, assumed to be at rest and in a fixed position.

16. Analysis of a sample of a covalent compound showed that it contained 14.4% hydrogen and 85.6% carbon by mass. What is the empirical formula for the compound?

Answers

Answer:a

Explanation:

What volume of 18.5 M nitric acid would be needed to make 25.0 mL of 3.0M?

Answers

Answer:What volume of 9.00 M nitric acid is needed to make 6.50 L of 1.25 M solution? 903 mL What molarity should the stock solution be if you want to dilute 25.0 mL to 2.00 L and have the final concentration be 0.103 M?

Explanation:

HELPPPP!!! I NEED HELP WITH SCIENCE

Answers

Answer:

Both are chemical changes.

Explanation:

They are chemical changes because when when you melt the sugar to make caramel a new substance is formed. The same with cookies. You don't start out with cookies, you start out with dough. And then when you cook the dough a new substance is formed which is the cookies.

Which equation shows the correct relationship between mass, force, and acceleration?

A
equation 1

B
equation 2

C
equation 3

D
equations 1, 2, and 3

Answers

The acceleration on an object is proportional to the resultant force and inversely proportional to the mass of the object  

Further explanation  

Newton's 2nd law explains that the acceleration produced by the resultant force on an object is proportional and in line with the resultant force and inversely proportional to the mass of the object  

∑F = m. a  

[tex]\large {\boxed {\bold {a = \frac {\sum F} {m}}}[/tex]

F = force, N  

m = mass = kg  

a = acceleration due to gravity, m / s²  

Newton's equation shows that the greater the net force applied to an object, the greater the acceleration, conversely the greater the mass of the object, the smaller the object's acceleration.

You can use this principle to choose the available answer options, because the questions are not complete

Help ASAP.................

Answers

I would say Oxygen because it’s a gas just like nitrogen.
Oxygen is the answer

Plants contain three types of tissue. Describe the function of each. What are the tissues made of?

Answers

Each plant organ (roots, stems, leaves) contains all three tissue types: ... Vascular tissue is made of two specialized conducting tissues: xylem and phloem. Xylem tissue transports water and nutrients from the roots to different parts of the plant, and also plays a role in structural support in the stem

PLEASE MARK ME AS BRAINLIEST

5) Titanium (11) oxide is produced from its elements

Answers

true. titanium oxide is a naturally occurring compound that is created when titanium reacts with the oxygen in the air.

Electronegativity difference of F and Cl:

ionic

covalent

Answers

Answer: Electronegativity difference of F and Cl: 1.0 and is covalent

Explanation:

Answer:

1.0, covalent

Explanation:

Electronegativity difference of N and H:

0.9

covalent

Electronegativity difference of F and Cl:

1.0

covalent

How are ions formed?

Answers

Answer: Ions are formed by the addition of electrons to, or the removal of electrons from,

Explanation:

Hydrogen gas is bubbled into a solution of barium hydroxide that has sulfur in it. The unbalanced equation for the reaction that takes place is: H2+S+OH- —-> S2- + H2O
What volume of 0.258 M Ba(OH)2 is required to react completely with 3.00g sulfur?

Answers

Volume of Ba(OH)₂ : 0.363 L

Further explanation

Balanced equation :

H₂(g)+S(s)+2OH⁻(aq)⇒ S²⁻(aq)+2H₂O(l) (eq 1)

Ba(OH)₂⇒Ba²⁺+2OH⁻ (eq 2)

mol S :

[tex]\tt \dfrac{3~g}{32~g/mol}=0.09375[/tex]

mol OH from eq 1 : (mol S : mol OH = 1 : 2)

[tex]\tt \dfrac{2}{1}\times 0.09375=0.1875[/tex]

mol Ba(OH)₂ from eq 2 : (mol Ba(OH)₂ : mol OH⁻=1 : 2)

[tex]\tt \dfrac{1}{2}\times 0.1875=0.09375[/tex]

volume of Ba(OH)₂ :

[tex]\tt Volume =\dfrac{mol}{M}=\dfrac{0.09375}{0.258}=0.363 L[/tex]

A sealed 10.0 L flask at 400 K contains equimolar amounts of ethane and propanol in gaseous form. Which of the following statements concerning the average molecular speed of ethane and propanol is true?

(A) The average molecular speed of ethane is less than the average molecular speed of propanol.
(B) The average molecular speed of ethane is greater than the average molecular speed of propanol.
(C) The average molecular speed of ethane is equal to the average molecular speed of propanol.
(D) The average molecular speeds of ethane and propanol cannot be compared without knowing the total pressure of the gas mixture.

Answers

Answer:

Im a 100% sure it is B. average molecular speed of ethane is greater than the average molecular speed of propanol.

Explanation:

Sry I didnt' get the explaination from my teacher.

According to the Kinetic theory of gases, the average speed of all gases at the same temperature will be in the same range. Hence, option C is correct.

What is kinetic theory of gases ?

Kinetic theory of gases states the properties and composition of gases at a temperature and pressure. According to this theory, gaseous substances are made of tiny particles which are free to move and collide to each other.

The kinetic energy of the particles is directly proportional to the temperature. Hence, as the temperature increases, the kinetic energy increases and their average molecular speed increases.

At the same temperature, all the gases have equal range of average molecular speed irrespective of their molecular weight. Hence, at 400 K the average molecular speed of ethane and propanol will be the same.

Find more on kinetic theory :

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Part of a chemical equation is shown below.

2KOH + H2SO4 → ?


Which pair of chemicals most likely comes after the arrow to complete the equation?

A. 2K + 2H2O

B. 2K2S + SO3

C. K2SO4 + 2HNO3

D. K2SO4 + 2H2O

Answers

Answer: the correct answer is D

Explanation: I just got the quiz finished

The products of the reaction has been potassium sulfate ([tex]\rm K_2SO_4[/tex]), and water ([tex]\rm H_2O[/tex]). Thus, option D is correct.

The chemical equation has been the representation of the reactants and the products formed. The reaction of KOH and sulfuric acid has been the neutralization reaction.

The products formed by the neutralization reaction has been salt and water.

The reaction of KOH and sulfuric acid has been:

[tex]\rm 2\;KOH\;+\;H_2SO_4\;\rightarrow\;K_2SO_4\;+\;2\;H_2O[/tex]

The products of the reaction has been potassium sulfate ([tex]\rm K_2SO_4[/tex]), and water ([tex]\rm H_2O[/tex]). Thus, option D is correct.

For more information about the chemical equation, refer to the link:

https://brainly.com/question/20492533

why are there more hours of daylight during the summer

Answers

Answer:

Because of daylight savings

Answer:

because during the summer is when the earth is tilted a certain one. But because in different places they get summer at a different time the earth tilts differently for the places around the world.

Explanation:

What is the density of an object, and what is an example of density?

Answers

If its density is less than water, it will float. For example, oak floats because its density is 0.7 g/cm³. If the density of an object is greater than water, it will sink.
Hope this helps

Which of the following would be considered a compound?
He
CI
NaCl
B

Answers

Answer:

NaCl

Explanation:

because He which is helium gas its an element alone,

Cl which is chlorine is a single element,

B which is Boron and its a single element,

but NaCl which is simply called table sugar is the combination between Na, sodium and Cl, chlorine , so its called a compound not an element.

What is the most common acid and base on earth?

Answers

Answer:

hydrochloride acid

Explanation:

hope this helps :D

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