Guys please help me i will mark brainly!

Use Table 1: Analysis of Decay in the laboratory guide to answer this question: Scientists find a piece of wood that is thought

Sladkaya [172]

<span>We are given the initial amount of 1 million carbon-14 atoms and the final amount which is 1/16 of the current atmospheric 14C levels. Also, the half life of carbon is </span>5,750 years. WE can use the decay formula

Aₓ = A₀e^-(ln2/t1/2)t
1,000,000(1/16) = (1,000,000)e^-(ln2/5750)t
t = 23,000 years

6 0

2 years ago

A 225 g sample of an unknown solid is heated 67C and placed into a calorimeter containing 25.6 g of water at 15.6°c. If the fina

Stella [2.4K]

Answer:

= 1.271 J/g°C

Explanation:

Heat released by the metal sample will be equivalent to the heat absorbed by water.

But heat = mass × specific heat capacity × temperature change

Thus;

Heat released by the solid;

= 225 g × c ×(67 -53) , where c is the specific heat capacity of the metal

= 3150 c joules

Heat absorbed by water;

= 25.6 g × 4.18 J/g°C × (53-15.6)

= 4002.0992 joules

Therefore;

3150 c joules = 4002.0992 joules

c =4002.0992/3150

6 0

2 years ago

An ordered list of chemical substances is shown.

alina1380 [7]

Answer : The correct option is, (C) 2, 4 and 5.

Explanation :

Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.

For example : Methane react with oxygen to give carbon dioxide and water.

$CH_4+2O_2\rightarrow CO_2+2H_2O$

In the given list of chemical substances, $CuO,Cu_2O,Li_2O$ are in oxide form. They can not be both reactant and product of a single combustion reaction.

In the given list, $C_2H_5NH_2$ is the only hydrocarbon which shows a combustion reaction. That means $C_2H_5NH_2$ react with $O_2$ to give $CO_2,H_2O$ and $N_2$ as a product.