Ask question

Ask question

All categories

2 years ago

9

i will give brainly to correct answer (if you dont get brainly lmk if you want me to make a fr33 p01nts post so i can give you i

t)

2 answers:

MrRissso [65]2 years ago

5 0

Answer:

The stoma allows the intake of oxygen gas in photosynthesis and releases oxygen gas in respiration.

Explanation:

Through photosynthesis, leaves turn light energy into food. Through pores, or stomata, leaves “breathe” in carbon dioxide and “breathe” out oxygen. Leaves also release excess water, much like we sweat.

LenaWriter [7]2 years ago

5 0

Your answer would be D!!!

You might be interested in

A first-order reaction has a half-life of 20.0 minutes. Starting with 1.00 × 1020 molecules of reactant at time t = 0, how many

zalisa [80]

Half-life time of a reaction is time at which reactant concentration becomes half of its initial value.

Half-life of the first order reaction is 20 min. Rate constant can be calculated as follows:

$K=\frac{0.6932}{t_{1/2}}=\frac{0.6932}{20 min}=0.03466 min^{-1}$

The rate expression for first order reaction is as follows:

$k=\frac{2.303}{t}log\frac{A_{0}}{A_{t}}$

initial number of molecules of reactant are $10^{20}$ , time is 100 min thus, putting the values to calculate number of reactant at time 100 min,

$0.03466 min^{-1}=\frac{2.303}{100 min}log\frac{[10^{20}]}{A_{t}}$

On rearranging,

$\frac{10^{20}}{A_{t}}=31.988$

Or,

$A_{t}=3.13\times 10^{18}$

Therefore, number of molecules unreacted will be $3.13\times 10^{18}$

7 0

3 years ago

What is the mass of a metal block with a volume of 3.1cm3 and a density of 3.82 g/cm3

zepelin [54]

Answer:

11.842g

Explanation:

To find mass the formula is volume times density.

4 0

3 years ago

A buffer is made that is .10M propanoic acid (pKa = 4.9) and .05M sodium propanoate. Calculate the pH.

inna [77]

PKa= 4.9 therefore ka= 10^-4.9= 1.259x10^-5

$ka= \frac{[H^+][CH3CH2COO^-]}{[CH3CH2COOH]}$

$[CH3CH2COO^-]
$ = 0.05
$[CH3CH2COOH]$ = 0.10

Therefore 1.259x10^-5 = $\frac{[H^+][0.05]}{[0.1]}$
Rearrange the equation to make the concentration of hydrogen the subject.
Therefore $[H^+] = \frac{(1.259*10^-5)(0.1)}{0.05}$

Therefore $[H^+]= 2.513*10^-5$

pH= -log [ $H^+$ ] = -log(2.513*10^-5)= 4.59.

7 0

3 years ago

Copper crystallizes in a face-centered cubic lattice (the Cu atoms are at the lattice points and at the face centers). If the de

Delvig [45]

Answer:

The unit cell edge lenght in pm is equal to 361 pm

Explanation:

Data provided:

ρ=Copper density=8.96 g/cm3

Atomic mass of copper=63.54 g/mol

Atoms/cell=4 atoms (in theory)

Avogadro's number=6.02x $10^{23}$ atoms/mol

Since copper has a cubic structure, its cell volume is equal to $a^{3}$ , which can be obtained through the relationship:

cell volume= $\frac{(atoms/cell)(atomic mass)}{(density)(Avogadros number)}$

Substituting the values:

cell volume= $\frac{(4 atoms)(63.54 g/mol)}{(8.96 g/cm3)(6.02x10^{23}) }=4.71x10^{-23}cm^{3}$

clearing, we have:

a= $\sqrt[3]{4.71x10^{-23}cm^{3} }=3.61x10^{-8}cm$

We convert from centimeter to picometer, 1cm=1x $10^{10}$ pm

a= $3.61x10^{-8}cmx\frac{1x10^{10}pm }{1cm} =361 pm$

8 0

3 years ago

What is th correct chemical symbol for nitrogen

postnew [5]

The correct symbol is N

3 0

3 years ago

Read 2 more answers