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2 years ago

What term refers to elements in group 18 that only react with other elements under special laboratory conditions?

Chemistry

2 answers:

baherus [9]2 years ago

6 0

I m so this for sure it’s halogens

Savatey [412]2 years ago

5 0

Answer:

Metalloids are found along the line between metals and non-metals on a periodic table. They are chemical elements that have properties in between those of metals and non-metals. ... Noble gases are all in group 18 on a periodic table.

Explanation:

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Which of these elements has the smallest atomic radius?

shutvik [7]

Answer:

Its Br on Ap ex

Explanation:

Just got it wrong ;( it's B

4 0

3 years ago

In one sentence, describe the general chemical structure of carbohydrates. In a second sentence, list the major biochemical func

Brums [2.3K]

Answer:

A carbohydrate is a compound composed of molecules of carbon (C), hydrogen (H), and oxygen (O) such that its general chemical formula is $CH_2OH$ .

Biochemical functions of carbohydrates: Carbohydrates provide Stored Energy, Carbohydrates help to preserve Muscle and promote digestive health and Carbohydrates build macromolecules

Explanation:

A carbohydrate is a compound composed of molecules of carbon (C), hydrogen (H), and oxygen (O) such that its general chemical formula is $CH_2OH$ .

Biochemical functions of carbohydrates:

1. Carbohydrates provide Stored Energy.

2. Carbohydrates help to preserve Muscle and promote digestive health.

3. Carbohydrates build macromolecules

6 0

2 years ago

3. Burns from boiling water can be severe, caused by the transfer of energy from the boiling water to the

Free_Kalibri [48]

Answer:

Q = 3937.56 J

Explanation:

Heat transferred due to change in temperature is given by :

$Q=mc\Delta T$

c is the specific heat of water, c=4.18 J/g-°C

We have, m = 15 g, $T_i=100^{\circ} C\ \text{and}\ T_f=37.2^{\circ} C$

So,

$Q=15\times 4.18\times (37.2-100)\\Q=-3937.56\ J$

Hence, 3937.56 J of heat is transferred.

8 0

3 years ago

I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19

IRINA_888 [86]

Answer:

A) Sample B has more calcium carbonate molecules

Explanation:

M = Molar mass of calcium carbonate = 100.0869 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

For the 4.12 g sample

Moles of a substance is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}$

Number of molecules is given by

$nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}$

For the 19.37 g sample

$n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}$

Number of molecules is given by

$nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}$

$1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}$

So, sample B has more calcium carbonate molecules.

The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.

7 0

3 years ago

What role does chlorophyll play in photosynthesis?

Elina [12.6K]

Chlorophyll captures the sun's energy and is used as energy to complete the photosynthesis process

4 0

2 years ago