True or False: the force of attraction that holds two atoms together is called a chemical bond

The brass cube has a mass of 67.2 grams. Each side is 2 cm long. What is the density of the brass cube? A) 2.8 g/cm 3 B) 3.15 g/

frutty [35]

The answer is D. 9.45 g/cm

4 0

3 years ago

What holds the two strands of a DNA molecule together?A. Ionic bonds between negatively and positively charged ionsB. Covalent b

statuscvo [17]

Answer:

D. Hydrogen bonds between complementary base pairs89

Explanation:

A DNA molecule is composed of two long polynucleotide chains made of four types of nucleotide subunits, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). These nucleotides are joined by covalent bonds forming a phosphate-sugar backbone. <em>These strands are held to one another with hydrogen bonds between the base portions of complementary nucleotides.</em>

I hope you find this information useful and interesting! Good luck!

8 0

3 years ago

Allison is trying to identify the type of bacteria found on common surfaces like doorknobs, table tops, etc. For this experiment

strojnjashka [21]

She would use a microscope

8 0

3 years ago

Read 2 more answers

Write the half-reactions as they occur at each electrode and the net cell reaction for this electrochemical cell containing indi

AlexFokin [52]

Explanation:

The given cell reaction is as follows.

$In(s)| In^{3+}(aq) || Cd^{2+}(aq) | Cd(s)$

Hence, reactions taking place at the cathode and anode are as follows.

At anode ; Oxidation-half reaction : $In(s) \rightarrow In^{3+}(aq) + 3e^{-}$ ...... (1)

At cathode; Reduction-half reaction : $Cd^{2+}(aq) + 2e^{-} \rightarrow Cd(s)$ ....... (2)

Hence, balance the half reactions by multiplying equation (1) by 2 and equation (2) by 3.

Therefore, net cell reaction is as follows.

$2In(s) \rightarrow 2In^{3+}(aq) + 6e^{-}$

$3Cd^{2+}(aq) + 6e^{-} \rightarrow 3Cd(s)$

Net reaction: $2In(s) + 3Cd^{2+}(aq) \rightarrow 2In^{3+}(aq) + 3Cd(s)$

Thus, we can conclude that the overall cell reaction is as follows.

$2In(s) + 3Cd^{2+}(aq) \rightarrow 2In^{3+}(aq) + 3Cd(s)$

4 0

3 years ago

38.25 grams of silicon is combined with 14.33 grams of nitrogen gas. How many grams of silicon nitride can be formed if nitrogen

zhuklara [117]

3Si + 2N2 --> Si3N4 (as given)

n(Si) = m/MM = 38.25/28.085 = 1.3619 mol
n(N2) = 14.33/2*14.007 = 0.5115 mol

Therefore, N2 is limiting and Si is in excess
The molar ratio of 2N2:Si3N4 is 2:1
So, 0.0575 mol of silicon nitride is formed (dividing 0.5115 by 2)

m of silicon nitride= n*mm = 0.0575*140.283 = 8.06627... g
= 8.066g (4 significant figures)

(hopefully it is right, but double check in case i did something wrong) :)

6 0

3 years ago