Why do different elements have different physical properties?

The difference in the number of protons and neutrons in atoms account for many of the different properties of elements. They are the glue that holds atoms together in chemical bonds. The basic electron number is determined by the number of protons.

Why are some elements gases at room temperature?

Elements that are gases at room temperature are all nonmetals (such as He, Ar, N2, O2, and so on). Compounds that are gases at room temperature are all covalent compounds (such as CO2, SO2, and NH3) that contain two or more nonmetals. With only rare exception, these gases have relatively small molecular weights.

What physical state are most elements in at room temperature?

Most of the metals are solids under “ordinary” conditions (i.e., 25ºC, 1 atmosphere of pressure, etc.), with the exception of mercury (Hg, element 80), which solidifies at -39ºC, and is a freely-flowing liquid at room temperature.

Why do elements change states?

State changes can happen when heat energy is applied to solids liquids and gases they all behave differently. When a substance is heated this causes the particles to vibrate and gain kinetic energy which can cause them to break away from each other changing state from solids to liquids to gas.

Why are elements so different from each other?

The number of protons in an atom is the defining feature of an atom. It’s what makes one element different from another. The number of protons in an atom is called its atomic number. All the elements in the universe are arranged according to their atomic number in the periodic table.

Why do elements in the same group have similar physical properties?

A vertical column in the periodic table of elements is called group. So, we can say that elements in a group have the same physical and chemical properties because their atoms have the same number of valence electrons or same valence shell electronic configuration.

Why are Group 8 elements gases at room temperature?

That’s because they have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.

How do you know the state of an element at room temperature?

If both its normal melting point and its normal boiling point are below room temperature (20°C), the substance is a gas under normal conditions. The normal melting point of oxygen is -218°C; its normal boiling point is -189°C. Oxygen is a gas at room temperature.

What’s the physical state of elements?

The strength of attraction between atoms in an element determines the physical state of an element. If the attraction between atoms is strong, the element will be a solid. If the attraction is less strong, the element will be a liquid. If the attraction is weak, the element will be a gas.

What is physical state of elements?

The three states of matter are the three distinct physical forms that matter can take in most environments: solid, liquid, and gas. In extreme environments, other states may be present, such as plasma, Bose-Einstein condensates, and neutron stars.

How can you differentiate the physical states of matter?

Solid is the state in which matter maintains a fixed volume and shape; liquid is the state in which matter adapts to the shape of its container but varies only slightly in volume; and gas is the state in which matter expands to occupy the volume and shape of its container.

Why are there different states of matter?

Adding or removing energy from matter causes a physical change as matter moves from one state to another. For example, adding thermal energy (heat) to liquid water causes it to become steam or vapor (a gas). And removing energy from liquid water causes it to become ice (a solid).

What is the physical state of elements at room temperature?

Physical States — Melting Points, Boiling Points, and Densities. In the periodic table above, black squares indicate elements which are solids at room temperature (about 22 C)*, those in blue squares are liquids at room temperature, and those in red squares are gases at room temperature.

How can you tell if an element is solid liquid or gas?

Look up a few periodic tables, most of them have some sort of color coding to distinguish whether the element is a solid, liquid or gas at 0 degrees Celsius and 1 atm, and all elements are in the same physical state at room temperature as at 0 degrees (gallium melts at a slightly higher temperature than room temperature)

What is the physical state of Group 7 elements?

The table shows the colour and physical states of chlorine, bromine and iodine at room temperature and pressure. The melting points and boiling points of the halogens increase going down group 7, and their colour gets darker. The group 7 elements exist as diatomic molecules.

Which properties can be observed or measured without changing the composition?

Physical properties can be observed or measured without changing the composition of matter. Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others. The three states of matter are: solid, liquid, and gas.